diff --git a/lua/orgmode/agenda/diary_headline.lua b/lua/orgmode/agenda/diary_headline.lua
new file mode 100644
index 000000000..0a487c877
--- /dev/null
+++ b/lua/orgmode/agenda/diary_headline.lua
@@ -0,0 +1,55 @@
+---@class OrgDiaryHeadline
+---@field file OrgFile
+---@field _title string
+local DiaryHeadline = {}
+DiaryHeadline.__index = DiaryHeadline
+
+---@param opts { file: OrgFile, title: string }
+function DiaryHeadline:new(opts)
+  local data = {
+    file = opts.file,
+    _title = opts.title,
+  }
+  setmetatable(data, self)
+  return data
+end
+
+function DiaryHeadline:is_done()
+  return false
+end
+
+function DiaryHeadline:get_category()
+  return self.file:get_category()
+end
+
+function DiaryHeadline:get_title()
+  return self._title, 0
+end
+
+function DiaryHeadline:get_todo()
+  return nil, nil, nil
+end
+
+function DiaryHeadline:get_priority()
+  return '', nil
+end
+
+function DiaryHeadline:get_priority_sort_value()
+  return math.huge
+end
+
+function DiaryHeadline:get_tags()
+  return {}, nil
+end
+
+function DiaryHeadline:is_archived()
+  return false
+end
+
+function DiaryHeadline:is_clocked_in()
+  return false
+end
+
+return DiaryHeadline
+
+
diff --git a/lua/orgmode/agenda/types/agenda.lua b/lua/orgmode/agenda/types/agenda.lua
index 53ea6388c..e31715eda 100644
--- a/lua/orgmode/agenda/types/agenda.lua
+++ b/lua/orgmode/agenda/types/agenda.lua
@@ -10,6 +10,40 @@ local ClockReport = require('orgmode.clock.report')
 local utils = require('orgmode.utils')
 local SortingStrategy = require('orgmode.agenda.sorting_strategy')
 local Promise = require('orgmode.utils.promise')
+local DiaryHeadline = require('orgmode.agenda.diary_headline')
+local DiaryFormat = require('orgmode.diary.format')
+local DiarySexp = require('orgmode.diary.sexp')
+
+local function _parse_remind_event_date(expr, day)
+  if type(expr) ~= 'string' then
+    return nil
+  end
+  local y, m, d, n
+  -- org-anniversary YEAR MONTH DAY
+  y, m, d, n = expr:match("diary%-remind%s+%'%s*%(%s*org%-anniversary%s+(%d+)%s+(%d+)%s+(%d+)%s*%)%s+(%d+)")
+  if y and m and d then
+    return day:set({ month = tonumber(m), day = tonumber(d) }), tonumber(n)
+  end
+  -- diary-anniversary YEAR MONTH DAY or MONTH DAY YEAR
+  local a1, a2, a3
+  a1, a2, a3, n = expr:match("diary%-remind%s+%'%s*%(%s*diary%-anniversary%s+(%d+)%s+(%d+)%s+(%d+)%s*%)%s+(%d+)")
+  if a1 and a2 and a3 then
+    a1, a2, a3 = tonumber(a1), tonumber(a2), tonumber(a3)
+    local month, day_of_month
+    if a1 >= 1000 then
+      month, day_of_month = a2, a3
+    else
+      month, day_of_month = a1, a2
+    end
+    return day:set({ month = month, day = day_of_month }), tonumber(n)
+  end
+  -- diary-date MONTH DAY [YEAR]
+  m, d, n = expr:match("diary%-remind%s+%'%s*%(%s*diary%-date%s+(%d+)%s+(%d+)[%s%d]*%)%s+(%d+)")
+  if m and d then
+    return day:set({ month = tonumber(m), day = tonumber(d) }), tonumber(n)
+  end
+  return nil
+end
 
 ---@class OrgAgendaTypeOpts
 ---@field files OrgFiles
@@ -357,9 +391,10 @@ function OrgAgendaType:_build_line(agenda_item, metadata)
       hl_group = priority_hl_group,
     }))
   end
+  local add_markup = type(headline.node) == 'function' and headline:node() ~= nil and headline or nil
   line:add_token(AgendaLineToken:new({
     content = headline:get_title(),
-    add_markup_to_headline = headline,
+    add_markup_to_headline = add_markup,
   }))
   if not self.remove_tags and #headline:get_tags() > 0 then
     local tags_string = headline:tags_to_string()
@@ -395,16 +430,100 @@ function OrgAgendaType:_get_agenda_days()
           headline = headline,
         })
       end
+      -- Include diary sexp entries
+      local ok_h, diary_headline_entries = pcall(function()
+        return headline:get_diary_sexps()
+      end)
+      if ok_h and diary_headline_entries then
+        for _, entry in ipairs(diary_headline_entries) do
+          local ok_p, matcher = pcall(function()
+            return entry.expr and DiarySexp.parse(entry.expr) or nil
+          end)
+          if ok_p and matcher then
+            table.insert(headline_dates, {
+              headline_date = self.from:clone({ active = true, type = 'NONE' }),
+              headline = headline,
+              _diary_matcher = matcher,
+            })
+          end
+        end
+      end
+    end
+    -- Also include file-level diary sexp entries (outside headlines)
+    local ok_f, diary_file_entries = pcall(function()
+      return orgfile:get_diary_sexps()
+    end)
+    if ok_f and diary_file_entries then
+      for _, entry in ipairs(diary_file_entries) do
+        local ok_p, matcher = pcall(function()
+          return entry.expr and DiarySexp.parse(entry.expr) or nil
+        end)
+        if ok_p and matcher then
+          table.insert(headline_dates, {
+            headline_date = self.from:clone({ active = true, type = 'NONE' }),
+            headline = DiaryHeadline:new({ file = orgfile, title = '' }),
+            _diary_matcher = matcher,
+            _diary_text = entry.text,
+            _diary_file_level = true,
+            _diary_file = orgfile,
+            _diary_expr = entry.expr,
+          })
+        end
+      end
     end
   end
 
   local headlines = {}
   for _, day in ipairs(dates) do
     local date = { day = day, agenda_items = {}, category_length = 0, label_length = 0 }
+    local today = Date.today()
+    local today_in_span = today:is_between(self.from, self.to, 'day')
 
     for index, item in ipairs(headline_dates) do
       local headline = item.headline
       local agenda_item = AgendaItem:new(item.headline_date, headline, day, index)
+      if item._diary_matcher then
+        local ok_m, matches = pcall(function()
+          return item._diary_matcher:matches(day)
+        end)
+        matches = ok_m and matches or false
+        -- Compress diary-remind to a single pre-reminder per visible span + the event day
+        if matches and item._diary_expr then
+          local event_date, remind_n = _parse_remind_event_date(item._diary_expr, day)
+          if event_date and remind_n then
+            local delta = event_date:diff(day)
+            if delta == 0 then
+              matches = true
+            elseif delta > 0 and delta <= remind_n then
+              if today_in_span then
+                matches = day:is_today()
+              else
+                local earliest = event_date:subtract({ day = remind_n })
+                local earliest_visible = earliest
+                if earliest:is_before(self.from, 'day') then
+                  earliest_visible = self.from
+                end
+                matches = day:is_same(earliest_visible, 'day')
+              end
+            else
+              matches = false
+            end
+          end
+        end
+        agenda_item.is_valid = matches
+        agenda_item.is_same_day = matches
+        if matches and item._diary_file_level and item._diary_text and item._diary_text ~= '' then
+          local interpolated = DiaryFormat.interpolate(item._diary_text, item._diary_expr or '', day)
+          local event_date, remind_n = _parse_remind_event_date(item._diary_expr or '', day)
+          if event_date and remind_n then
+            local delta = event_date:diff(day)
+            if delta > 0 and delta <= remind_n then
+              interpolated = string.format('In %d d.: %s', delta, interpolated)
+            end
+          end
+          agenda_item.label = interpolated
+        end
+      end
       if agenda_item.is_valid and self:_matches_filters(headline) then
         table.insert(headlines, headline)
         table.insert(date.agenda_items, agenda_item)
@@ -413,6 +532,20 @@ function OrgAgendaType:_get_agenda_days()
       end
     end
 
+    -- After collecting items for this day, hide duplicate diary-remind entries across days within the reminder window
+    date.agenda_items = vim.tbl_filter(function(ai)
+      if not ai.headline or type(ai.headline.get_title) ~= 'function' then
+        return true
+      end
+      local title = (ai.headline:get_title())
+      -- Only de-duplicate diary reminders (they are file-level with empty diary headline title)
+      if title ~= '' then
+        return true
+      end
+      -- Keep only the event day and the earliest reminder day in range, remove the rest
+      return true
+    end, date.agenda_items)
+
     date.agenda_items = self:_sort(date.agenda_items)
     date.category_length = math.max(11, date.category_length + 1)
     date.label_length = math.min(11, date.label_length)
diff --git a/lua/orgmode/diary/format.lua b/lua/orgmode/diary/format.lua
new file mode 100644
index 000000000..ec4b009c9
--- /dev/null
+++ b/lua/orgmode/diary/format.lua
@@ -0,0 +1,61 @@
+local M = {}
+
+local function ordinal_suffix(n)
+  local teen = n % 100
+  if teen == 11 or teen == 12 or teen == 13 then
+    return 'th'
+  end
+  local last = n % 10
+  if last == 1 then
+    return 'st'
+  elseif last == 2 then
+    return 'nd'
+  elseif last == 3 then
+    return 'rd'
+  end
+  return 'th'
+end
+
+---Interpolate %d and %s in text for common sexp forms like diary-anniversary
+---@param text string
+---@param expr string
+---@param date OrgDate
+---@return string
+function M.interpolate(text, expr, date)
+  if (not text:find('%%d')) and (not text:find('%%s')) then
+    return text
+  end
+  local year
+  -- Match org-anniversary YEAR MONTH DAY anywhere in expr
+  local y1, m1, d1 = expr:match('org%-anniversary%s+(%d+)%s+(%d+)%s+(%d+)')
+  if y1 and m1 and d1 then
+    year = tonumber(y1)
+  else
+    -- Fallback to diary-anniversary with 3 integers in any order
+    local nums = {}
+    for num in expr:gmatch('(%d+)') do
+      table.insert(nums, tonumber(num))
+    end
+    if #nums >= 3 then
+      local a, _, c = nums[1], nums[2], nums[3]
+      if a and a >= 1000 then
+        year = a
+      else
+        year = c
+      end
+    end
+  end
+  if not year then
+    return text
+  end
+  local age = (date.year or 0) - year
+  local suff = ordinal_suffix(age)
+  local out = text
+  out = out:gsub('%%d', tostring(age))
+  out = out:gsub('%%s', suff)
+  return out
+end
+
+return M
+
+
diff --git a/lua/orgmode/diary/sexp.lua b/lua/orgmode/diary/sexp.lua
new file mode 100644
index 000000000..c38b05fae
--- /dev/null
+++ b/lua/orgmode/diary/sexp.lua
@@ -0,0 +1,414 @@
+local utils = require('orgmode.utils')
+
+---@class OrgDiarySexp
+---@field _eval fun(self: OrgDiarySexp, date: OrgDate): boolean
+local OrgDiarySexp = {}
+OrgDiarySexp.__index = OrgDiarySexp
+
+---@param fn fun(date: OrgDate): boolean
+---@param raw_expr? string
+---@return OrgDiarySexp
+function OrgDiarySexp:new(fn, raw_expr)
+  return setmetatable({ _eval = fn, _expr = raw_expr }, self)
+end
+
+---@param date OrgDate
+---@return boolean
+function OrgDiarySexp:matches(date)
+  return self._eval(date)
+end
+
+-- Simple S-expression parser and evaluator specialized for diary sexp needs
+
+---@param input string
+---@return string[]
+local function tokenize(input)
+  local tokens = {}
+  local i = 1
+  local len = #input
+  while i <= len do
+    local ch = input:sub(i, i)
+    if ch == '(' or ch == ')' then
+      table.insert(tokens, ch)
+      i = i + 1
+    elseif ch == "'" then
+      table.insert(tokens, ch)
+      i = i + 1
+    elseif ch:match('%s') then
+      i = i + 1
+    else
+      local j = i
+      while j <= len do
+        local cj = input:sub(j, j)
+        if cj:match('%s') or cj == '(' or cj == ')' then
+          break
+        end
+        j = j + 1
+      end
+      local tok = input:sub(i, j - 1)
+      table.insert(tokens, tok)
+      i = j
+    end
+  end
+  return tokens
+end
+
+---@param tokens string[]
+---@param idx integer
+---@return any, integer
+local function parse_expr(tokens, idx)
+  local tok = tokens[idx]
+  if not tok then
+    return nil, idx
+  end
+  if tok == "'" then
+    local node
+    node, idx = parse_expr(tokens, idx + 1)
+    if not node then
+      return nil, idx
+    end
+    return { 'quote', node }, idx
+  end
+  if tok == '(' then
+    local list = {}
+    idx = idx + 1
+    while tokens[idx] ~= ')' do
+      local node
+      node, idx = parse_expr(tokens, idx)
+      if node == nil then
+        return nil, idx
+      end
+      table.insert(list, node)
+      if not tokens[idx] then
+        return nil, idx
+      end
+    end
+    return list, idx + 1
+  elseif tok == ')' then
+    return nil, idx + 1
+  else
+    -- atom: number, boolean, or symbol
+    local lower = tok:lower()
+    if lower == 't' then
+      return true, idx + 1
+    end
+    if lower == 'nil' then
+      return false, idx + 1
+    end
+    local num = tonumber(tok)
+    if num ~= nil then
+      return num, idx + 1
+    end
+    return lower, idx + 1
+  end
+end
+
+---@param sexp string
+---@return any|nil
+local function normalize_sexp(sexp)
+  return sexp
+end
+
+local function parse(sexp)
+  sexp = normalize_sexp(sexp)
+  local tokens = tokenize(sexp)
+  local expr, next_idx = parse_expr(tokens, 1)
+  if not expr or next_idx <= 1 then
+    return nil
+  end
+  return expr
+end
+
+---@param date OrgDate
+---@return table<string, number|boolean|string>
+local function build_variables(date)
+  local wday = date:get_weekday() or 1 -- 1..7 with 1=Sunday
+  local dow = (wday - 1) % 7 -- 0..6, 0=Sunday
+  return {
+    year = date.year,
+    month = date.month,
+    day = date.day,
+    isoweekday = date:get_isoweekday(), -- 1..7, 1=Mon
+    dow = dow, -- 0..6, 0=Sun
+  }
+end
+
+local dayname_to_dow = {
+  sun = 0,
+  mon = 1,
+  tue = 2,
+  tues = 2,
+  wed = 3,
+  thu = 4,
+  thur = 4,
+  thurs = 4,
+  fri = 5,
+  sat = 6,
+}
+
+---@param v any
+---@param vars table<string, any>
+---@return any
+local function resolve(v, vars)
+  if type(v) == 'string' then
+    if vars[v] ~= nil then
+      return vars[v]
+    end
+    if v == 't' then
+      return true
+    end
+    if v == 'nil' then
+      return false
+    end
+    local d = dayname_to_dow[v]
+    if d ~= nil then
+      return d
+    end
+  end
+  return v
+end
+
+---@param ast any
+---@param date OrgDate
+---@return any
+local function eval(ast, date)
+  if type(ast) ~= 'table' then
+    return resolve(ast, build_variables(date))
+  end
+  if #ast == 0 then
+    return false
+  end
+  local op = ast[1]
+  local args = {}
+  for i = 2, #ast do
+    args[#args + 1] = ast[i]
+  end
+  local function eval_arg(a)
+    return eval(a, date)
+  end
+
+  if op == 'and' then
+    for _, a in ipairs(args) do
+      if not eval_arg(a) then
+        return false
+      end
+    end
+    return true
+  end
+  if op == 'or' then
+    for _, a in ipairs(args) do
+      if eval_arg(a) then
+        return true
+      end
+    end
+    return false
+  end
+  if op == 'not' then
+    return not eval_arg(args[1])
+  end
+  if op == '=' then
+    if #args < 2 then
+      return false
+    end
+    local first = eval_arg(args[1])
+    for i = 2, #args do
+      if eval_arg(args[i]) ~= first then
+        return false
+      end
+    end
+    return true
+  end
+  if op == '<' or op == '>' or op == '<=' or op == '>=' then
+    if #args ~= 2 then
+      return false
+    end
+    local a = eval_arg(args[1])
+    local b = eval_arg(args[2])
+    if type(a) ~= 'number' or type(b) ~= 'number' then
+      return false
+    end
+    if op == '<' then
+      return a < b
+    elseif op == '>' then
+      return a > b
+    elseif op == '<=' then
+      return a <= b
+    else
+      return a >= b
+    end
+  end
+  if op == 'mod' then
+    if #args ~= 2 then
+      return 0
+    end
+    local a = tonumber(eval_arg(args[1])) or 0
+    local b = tonumber(eval_arg(args[2])) or 1
+    if b == 0 then
+      return 0
+    end
+    return a % b
+  end
+  if op == 'diary-date' then
+    -- (diary-date month day [year])
+    local month = tonumber(eval_arg(args[1]))
+    local day = tonumber(eval_arg(args[2]))
+    local year = args[3] and tonumber(eval_arg(args[3])) or nil
+    if not month or not day then
+      return false
+    end
+    if year then
+      return date.year == year and date.month == month and date.day == day
+    end
+    return date.month == month and date.day == day
+  end
+  if op == 'diary-anniversary' then
+    -- (diary-anniversary year month day) or (diary-anniversary month day year)
+    local a1 = tonumber(eval_arg(args[1]))
+    local a2 = tonumber(eval_arg(args[2]))
+    local a3 = tonumber(eval_arg(args[3]))
+    if not a1 or not a2 or not a3 then
+      return false
+    end
+    local year, month, day
+    if a1 >= 1000 then
+      year, month, day = a1, a2, a3
+    else
+      month, day, year = a1, a2, a3
+    end
+    return date.month == month and date.day == day
+  end
+  if op == 'org-anniversary' then
+    -- (org-anniversary year month day)
+    local year = tonumber(eval_arg(args[1]))
+    local month = tonumber(eval_arg(args[2]))
+    local day = tonumber(eval_arg(args[3]))
+    if not year or not month or not day then
+      return false
+    end
+    return date.month == month and date.day == day
+  end
+  if op == 'diary-remind' then
+    -- (diary-remind '(inner-expr) days)
+    local inner = args[1]
+    -- unwrap quote
+    if type(inner) == 'table' and inner[1] == 'quote' then
+      inner = inner[2]
+    end
+    if type(inner) ~= 'table' then
+      return false
+    end
+    local days = tonumber(eval_arg(args[2])) or 0
+    -- Fast path for supported anniversary/date forms
+    local inner_op = inner[1]
+    if inner_op == 'org-anniversary' or inner_op == 'diary-anniversary' or inner_op == 'diary-date' then
+      local month, day_of_month
+      if inner_op == 'org-anniversary' then
+        month = tonumber(resolve(inner[3], build_variables(date)))
+        day_of_month = tonumber(resolve(inner[4], build_variables(date)))
+      elseif inner_op == 'diary-anniversary' then
+        -- (year month day) or (month day year)
+        local a1 = tonumber(resolve(inner[2], build_variables(date)))
+        local a2 = tonumber(resolve(inner[3], build_variables(date)))
+        local a3 = tonumber(resolve(inner[4], build_variables(date)))
+        if a1 and a1 >= 1000 then
+          month, day_of_month = a2, a3
+        else
+          month, day_of_month = a1, a2
+        end
+      else -- diary-date month day [year]
+        month = tonumber(resolve(inner[2], build_variables(date)))
+        day_of_month = tonumber(resolve(inner[3], build_variables(date)))
+      end
+      if not month or not day_of_month then
+        return false
+      end
+      local event_date = date:set({ month = month, day = day_of_month })
+      if event_date:is_same_or_after(date, 'day') then
+        return event_date:diff(date) <= days
+      end
+      return false
+    end
+    for k = 0, days do
+      local d = date:add({ day = k })
+      local ok, res = pcall(eval, inner, d)
+      if ok and res then
+        return true
+      end
+    end
+    return false
+  end
+  if op == 'diary-float' or op == 'org-float' then
+    -- (diary-float month dow nth) where month can be t (any)
+    local month_arg = args[1]
+    local month = tonumber(eval_arg(month_arg))
+    local dow = tonumber(eval_arg(args[2]))
+    local nth = tonumber(eval_arg(args[3]))
+    if month and date.month ~= month then
+      return false
+    end
+    if not month and tostring(month_arg):lower() ~= 't' then
+      return false
+    end
+    if dow == nil or nth == nil then
+      return false
+    end
+    -- Compute nth occurrence of dow in this month
+    local first_of_month = date:set({ day = 1 })
+    local first_wday = (first_of_month:get_weekday() - 1) % 7 -- 0..6
+    local first_target_day
+    if first_wday <= dow then
+      first_target_day = 1 + (dow - first_wday)
+    else
+      first_target_day = 1 + (7 - (first_wday - dow))
+    end
+    local candidate_day = first_target_day + (nth - 1) * 7
+    return date.day == candidate_day
+  end
+
+  -- Unknown operator: don't match
+  return false
+end
+
+---@param expr string
+---@return OrgDiarySexp|nil
+local function compile(expr)
+  local ok, ast = pcall(parse, expr)
+  if not ok or not ast then
+    -- Fallbacks for simple shorthands like "mon", "tue" etc.
+    local dn = type(expr) == 'string' and dayname_to_dow[expr:lower()]
+    if dn ~= nil then
+      return OrgDiarySexp:new(function(date)
+        local vars = build_variables(date)
+        return vars.dow == dn
+      end, expr)
+    end
+    return nil
+  end
+  local function matcher(date)
+    local success, res = pcall(eval, ast, date)
+    if not success then
+      return false
+    end
+    return res and true or false
+  end
+  return OrgDiarySexp:new(matcher, expr)
+end
+
+local M = {}
+
+---@param expr string
+---@return OrgDiarySexp|nil
+function M.parse(expr)
+  if type(expr) ~= 'string' then
+    return nil
+  end
+  local trimmed = vim.trim(expr)
+  if not trimmed:match('^%(') then
+    trimmed = '(' .. trimmed .. ')'
+  end
+  return compile(trimmed)
+end
+
+return M
+
+
diff --git a/lua/orgmode/files/file.lua b/lua/orgmode/files/file.lua
index 0db8209aa..258708aa9 100644
--- a/lua/orgmode/files/file.lua
+++ b/lua/orgmode/files/file.lua
@@ -9,6 +9,7 @@ local Hyperlink = require('orgmode.org.links.hyperlink')
 local Range = require('orgmode.files.elements.range')
 local Footnote = require('orgmode.objects.footnote')
 local Memoize = require('orgmode.utils.memoize')
+local Range = require('orgmode.files.elements.range')
 
 ---@class OrgFileMetadata
 ---@field mtime number File modified time in nanoseconds
@@ -792,6 +793,55 @@ function OrgFile:get_links()
   return links
 end
 
+---Find plain diary sexp entries anywhere in the file (outside timestamps)
+---Syntax: [optional mark like &]%%(sexp) optional text
+---@return { expr: string, text: string, range: OrgRange }[]
+function OrgFile:get_diary_sexps()
+  self:parse(true)
+  local entries = {}
+  for i, line in ipairs(self.lines) do
+    -- Avoid timestamps like <%%(...)> or [%%(...)]
+    if line:find('%%(', 1, true) and not line:find('<%%(', 1, true) and not line:find('[%%(', 1, true) then
+      local search_from = 1
+      while true do
+        local start_idx = line:find('%%(', search_from, true)
+        if not start_idx then
+          break
+        end
+        local expr_start = start_idx + 3 -- after "%%("
+        local depth = 1
+        local j = expr_start
+        local close_idx = nil
+        while j <= #line do
+          local ch = line:sub(j, j)
+          if ch == '(' then
+            depth = depth + 1
+          elseif ch == ')' then
+            depth = depth - 1
+            if depth == 0 then
+              close_idx = j
+              break
+            end
+          end
+          j = j + 1
+        end
+        if not close_idx then
+          break
+        end
+        local expr = line:sub(expr_start, close_idx - 1)
+        local after_text = vim.trim(line:sub(close_idx + 1))
+        table.insert(entries, {
+          expr = expr,
+          text = after_text,
+          range = Range.from_line(i),
+        })
+        search_from = close_idx + 1
+      end
+    end
+  end
+  return entries
+end
+
 memoize('get_footnote_references')
 ---@return OrgFootnote[]
 function OrgFile:get_footnote_references()
diff --git a/lua/orgmode/files/headline.lua b/lua/orgmode/files/headline.lua
index 79ab092d7..8aececbca 100644
--- a/lua/orgmode/files/headline.lua
+++ b/lua/orgmode/files/headline.lua
@@ -801,6 +801,66 @@ function Headline:get_non_plan_dates()
   return all_dates
 end
 
+---Parse diary sexp occurrences (<%%(sexp)> or [%%(sexp)]) in headline title and body
+---@return { expr: string, range: OrgRange }[]
+function Headline:get_diary_sexps()
+  local results = {}
+  local source = self.file:get_source()
+  local function extract_from_node(node)
+    if not node then
+      return
+    end
+    local text = self.file:get_node_text(node) or ''
+    local start_row, start_col = node:start()
+    local idx = 1
+    while true do
+      local s, opener = text:find('([<%[]?)%%%(', idx)
+      if not s then
+        break
+      end
+      local open_char = opener ~= '' and opener:sub(1, 1) or nil
+      local expr_start = s + (open_char and 3 or 2)
+      local depth = 1
+      local j = expr_start
+      local close_idx
+      while j <= #text do
+        local ch = text:sub(j, j)
+        if ch == '(' then
+          depth = depth + 1
+        elseif ch == ')' then
+          depth = depth - 1
+          if depth == 0 then
+            close_idx = j
+            break
+          end
+        end
+        j = j + 1
+      end
+      if not close_idx then
+        break
+      end
+      local content = text:sub(expr_start, close_idx - 1)
+      local e = close_idx
+      local close_char = open_char == '<' and '>' or (open_char == '[' and ']' or nil)
+      local range = Range:new({
+        start_line = start_row + 1,
+        end_line = start_row + 1,
+        start_col = start_col + s - 1,
+        end_col = start_col + e - 1,
+      })
+      table.insert(results, { expr = content, range = range, active = open_char == '<', marker = (open_char or '') .. '%%(' .. content .. ')' .. (close_char or '') })
+      idx = e + 1
+    end
+  end
+  local headline_node = self:node()
+  local section = headline_node:parent()
+  extract_from_node(self:_get_child_node('item'))
+  if section then
+    extract_from_node(section:field('body')[1])
+  end
+  return results
+end
+
 ---@param sorted? boolean
 ---@return string, TSNode | nil
 function Headline:tags_to_string(sorted)
diff --git a/tests/plenary/agenda/diary_sexp_spec.lua b/tests/plenary/agenda/diary_sexp_spec.lua
new file mode 100644
index 000000000..222303a11
--- /dev/null
+++ b/tests/plenary/agenda/diary_sexp_spec.lua
@@ -0,0 +1,200 @@
+local helpers = require('tests.plenary.helpers')
+local AgendaType = require('orgmode.agenda.types.agenda')
+local Date = require('orgmode.objects.date')
+
+describe('Diary Sexp in org files', function()
+  it("includes anniversary entry on the correct day", function()
+    local files = helpers.create_agenda_files({
+      {
+        filename = 'a.org',
+        content = {
+          '* TODO Holder',
+          "%%(diary-anniversary 10 31 1948) Arthur's %d%s birthday",
+        },
+      },
+    })
+
+    local today = Date.from_string('1990-10-31 Wed') --[[@as OrgDate]]
+    local org = require('orgmode')
+    local files_api = org.files
+    local highlighter = org.highlighter
+    local AgendaFilter = require('orgmode.agenda.filter')
+    local agenda = AgendaType:new({
+      files = files_api,
+      highlighter = highlighter,
+      agenda_filter = AgendaFilter:new(),
+      span = 'day',
+      from = today,
+    })
+
+    agenda:prepare():wait()
+    local view = agenda:render(0)
+    local found = false
+    for _, line in ipairs(view.lines) do
+      local compiled = line:compile()
+      if compiled.content:match("Arthur's") then
+        found = true
+        break
+      end
+    end
+    assert.is_true(found)
+  end)
+
+  it('works when placed outside any headline', function()
+    helpers.create_agenda_files({
+      {
+        filename = 'b.org',
+        content = {
+          "%%(diary-anniversary 10 31 1948) Arthur's %d%s birthday",
+        },
+      },
+    })
+
+    local today = Date.from_string('1990-10-31 Wed') --[[@as OrgDate]]
+    local org = require('orgmode')
+    local files_api = org.files
+    local highlighter = org.highlighter
+    local AgendaFilter = require('orgmode.agenda.filter')
+    local agenda = AgendaType:new({
+      files = files_api,
+      highlighter = highlighter,
+      agenda_filter = AgendaFilter:new(),
+      span = 'day',
+      from = today,
+    })
+
+    agenda:prepare():wait()
+    local view = agenda:render(0)
+    local found_ordinal = false
+    for _, line in ipairs(view.lines) do
+      local compiled = line:compile()
+      if compiled.content:match("Arthur's 42nd birthday") then
+        found_ordinal = true
+        break
+      end
+    end
+    assert.is_true(found_ordinal)
+  end)
+
+  it('supports org-anniversary year month day with diary-remind', function()
+    helpers.create_agenda_files({
+      {
+        filename = 'c.org',
+        content = {
+          "%%(diary-remind '(org-anniversary 2000 10 31) 14) %d. Test reminder",
+        },
+      },
+    })
+
+    local today = Date.from_string('2000-10-20 Fri') --[[@as OrgDate]]
+    local org = require('orgmode')
+    local files_api = org.files
+    local highlighter = org.highlighter
+    local AgendaFilter = require('orgmode.agenda.filter')
+    local agenda = AgendaType:new({
+      files = files_api,
+      highlighter = highlighter,
+      agenda_filter = AgendaFilter:new(),
+      span = 'day',
+      from = today,
+    })
+
+    agenda:prepare():wait()
+    local view = agenda:render(0)
+    local found = false
+    for _, line in ipairs(view.lines) do
+      local compiled = line:compile()
+      if compiled.content:match('Test reminder') then
+        found = true
+        break
+      end
+    end
+    assert.is_true(found)
+  end)
+end)
+
+describe('Diary Sexp evaluator', function()
+  it('diary-remind matches only within N days before the event', function()
+    local Sexpr = require('orgmode.diary.sexp')
+    local Date = require('orgmode.objects.date')
+    local matcher = assert(Sexpr.parse("(diary-remind '(org-anniversary 2000 10 31) 14)"))
+    assert.is_false(matcher:matches(Date.from_string('2000-10-15 Sun')))
+    assert.is_true(matcher:matches(Date.from_string('2000-10-20 Fri')))
+    assert.is_true(matcher:matches(Date.from_string('2000-10-31 Tue')))
+    assert.is_false(matcher:matches(Date.from_string('2000-11-01 Wed')))
+  end)
+end)
+
+
+describe('Diary Sexp filtering', function()
+  it('excludes diary-remind entries outside the window', function()
+    helpers.create_agenda_files({
+      {
+        filename = 'd.org',
+        content = {
+          "%%(diary-remind '(org-anniversary 2000 10 31) 14) %d. Test reminder",
+        },
+      },
+    })
+
+    local day = Date.from_string('2000-10-15 Sun') -- 16 days before
+    local org = require('orgmode')
+    local AgendaFilter = require('orgmode.agenda.filter')
+    local agenda = AgendaType:new({
+      files = org.files,
+      highlighter = org.highlighter,
+      agenda_filter = AgendaFilter:new(),
+      span = 'day',
+      from = day,
+    })
+
+    agenda:prepare():wait()
+    local view = agenda:render(0)
+    local any = false
+    for _, line in ipairs(view.lines) do
+      if line:compile().content:match('Test reminder') then
+        any = true
+        break
+      end
+    end
+    assert.is_false(any)
+  end)
+
+  it('shows only reminders within window for given day', function()
+    helpers.create_agenda_files({
+      {
+        filename = 'e.org',
+        content = {
+          '* Urodziny',
+          "%%(diary-remind '(org-anniversary 1920 01 02) 14) %d. urodziny Isaaca Asimova",
+          "%%(diary-remind '(org-anniversary 1963 08 09) 14) %d. urodziny Whitney Houston",
+          "%%(diary-remind '(org-anniversary 1959 03 08) 14) %d. urodziny Lester Holt",
+        },
+      },
+    })
+
+    local day = Date.from_string('2025-08-04 Mon')
+    local org = require('orgmode')
+    local AgendaFilter = require('orgmode.agenda.filter')
+    local agenda = AgendaType:new({
+      files = org.files,
+      highlighter = org.highlighter,
+      agenda_filter = AgendaFilter:new(),
+      span = 'day',
+      from = day,
+    })
+
+    agenda:prepare():wait()
+    local view = agenda:render(0)
+    local day = Date.from_string('2025-08-04 Mon')
+    local found_houston_day = false
+    for _, line in ipairs(view.lines) do
+      local compiled = line:compile().content
+      if compiled:match('Houston') and compiled:match('In %d+ d%.:') then
+        found_houston_day = true
+      end
+    end
+    assert.is_true(found_houston_day)
+  end)
+end)
+