fix(util): resolve timezone issue in format_time function

The format_time function was always returning full timestamps due to a timezone offset bug.

The original code mixed UTC time construction (os.time with date tables) and local time parsing (os.date '*t'), creating inconsistent comparisons.

Author: sudo-tee

lua/opencode/util.lua

@@ -133,10 +133,7 @@ function M.format_time(timestamp)
     timestamp = math.floor(timestamp / 1000)
   end
 
-  local local_t = os.date('*t') --[[@as std.osdateparam]]
-  local today_start = os.time({ year = local_t.year, month = local_t.month, day = local_t.day })
-
-  if timestamp >= today_start then
+  if os.date('%Y-%m-%d', timestamp) == os.date('%Y-%m-%d') then
     return os.date('%I:%M %p', timestamp) --[[@as string]]
   end
 

tests/unit/util_spec.lua

@@ -53,11 +53,17 @@ describe('util.parse_run_args', function()
   end)
 
   it('parses multiple prefixes in order', function()
-    local opts, prompt = util.parse_run_args({ 'agent=plan', 'model=openai/gpt-4', 'context=current_file.enabled=false', 'prompt', 'here' })
+    local opts, prompt = util.parse_run_args({
+      'agent=plan',
+      'model=openai/gpt-4',
+      'context=current_file.enabled=false',
+      'prompt',
+      'here',
+    })
     assert.are.same({
       agent = 'plan',
       model = 'openai/gpt-4',
-      context = { current_file = { enabled = false } }
+      context = { current_file = { enabled = false } },
     }, opts)
     assert.equals('prompt here', prompt)
   end)
@@ -67,8 +73,8 @@ describe('util.parse_run_args', function()
     assert.are.same({
       context = {
         current_file = { enabled = false },
-        selection = { enabled = true }
-      }
+        selection = { enabled = true },
+      },
     }, opts)
     assert.equals('test', prompt)
   end)
@@ -91,3 +97,155 @@ describe('util.parse_run_args', function()
     assert.equals('some prompt model=openai/gpt-4', prompt)
   end)
 end)
+
+describe('util.format_time', function()
+  local function make_timestamp(year, month, day, hour, min, sec)
+    return os.time({ year = year, month = month, day = day, hour = hour or 0, min = min or 0, sec = sec or 0 })
+  end
+
+  local today = os.date('*t')
+  local today_morning = make_timestamp(today.year, today.month, today.day, 8, 30, 0)
+  local today_afternoon = make_timestamp(today.year, today.month, today.day, 15, 45, 30)
+  local today_evening = make_timestamp(today.year, today.month, today.day, 23, 59, 59)
+
+  local yesterday = os.time() - 86400 -- 24 hours ago
+  local last_week = os.time() - (7 * 86400) -- 7 days ago
+  local next_year = make_timestamp(today.year + 1, 6, 15, 12, 0, 0)
+
+  describe('today timestamps', function()
+    it('formats morning time correctly', function()
+      local result = util.format_time(today_morning)
+      assert.matches('^%d%d?:%d%d [AP]M$', result)
+      assert.is_nil(result:match('%d%d%d%d'))
+    end)
+
+    it('formats afternoon time correctly', function()
+      local result = util.format_time(today_afternoon)
+      assert.matches('^%d%d?:%d%d [AP]M$', result)
+      assert.is_nil(result:match('%d%d%d%d'))
+    end)
+
+    it('formats late evening time correctly', function()
+      local result = util.format_time(today_evening)
+      assert.matches('^%d%d?:%d%d [AP]M$', result)
+      assert.is_nil(result:match('%d%d%d%d'))
+    end)
+
+    it('formats current time as time-only', function()
+      local current_time = os.time()
+      local result = util.format_time(current_time)
+      assert.matches('^%d%d?:%d%d [AP]M$', result)
+      assert.is_nil(result:match('%d%d%d%d'))
+    end)
+  end)
+
+  describe('other day timestamps', function()
+    it('formats yesterday with full date', function()
+      local result = util.format_time(yesterday)
+      assert.matches('^%d%d? %a%a%a %d%d%d%d %d%d?:%d%d [AP]M$', result)
+      assert.matches('%d%d%d%d', result)
+    end)
+
+    it('formats last week with full date', function()
+      local result = util.format_time(last_week)
+      assert.matches('^%d%d? %a%a%a %d%d%d%d %d%d?:%d%d [AP]M$', result)
+      assert.matches('%d%d%d%d', result)
+    end)
+
+    it('formats future date with full date', function()
+      local result = util.format_time(next_year)
+      assert.matches('^%d%d? %a%a%a %d%d%d%d %d%d?:%d%d [AP]M$', result)
+      assert.matches('%d%d%d%d', result)
+    end)
+  end)
+
+  describe('millisecond timestamp conversion', function()
+    it('converts millisecond timestamps to seconds', function()
+      local seconds_timestamp = os.time()
+      local milliseconds_timestamp = seconds_timestamp * 1000
+
+      local seconds_result = util.format_time(seconds_timestamp)
+      local milliseconds_result = util.format_time(milliseconds_timestamp)
+
+      assert.equals(seconds_result, milliseconds_result)
+    end)
+
+    it('handles large millisecond timestamps correctly', function()
+      local ms_timestamp = 1762350000000 -- ~November 2025 in milliseconds
+      local result = util.format_time(ms_timestamp)
+
+      assert.is_not_nil(result)
+      assert.is_string(result)
+
+      local is_time_only = result:match('^%d%d?:%d%d [AP]M$')
+      local is_full_date = result:match('^%d%d? %a%a%a %d%d%d%d %d%d?:%d%d [AP]M$')
+      assert.is_true(is_time_only ~= nil or is_full_date ~= nil)
+    end)
+
+    it('does not convert regular second timestamps', function()
+      local small_timestamp = 1000000000 -- Year 2001, definitely in seconds
+      local result = util.format_time(small_timestamp)
+
+      -- Should format without error
+      assert.is_not_nil(result)
+      assert.is_string(result)
+    end)
+  end)
+
+  describe('edge cases', function()
+    it('handles midnight correctly', function()
+      local midnight = make_timestamp(today.year, today.month, today.day, 0, 0, 0)
+      local result = util.format_time(midnight)
+
+      if os.date('%Y-%m-%d', midnight) == os.date('%Y-%m-%d') then
+        assert.matches('^%d%d?:%d%d [AP]M$', result)
+        assert.matches('12:00 AM', result) -- Midnight should be 12:00 AM
+      else
+        assert.matches('^%d%d? %a%a%a %d%d%d%d %d%d?:%d%d [AP]M$', result)
+      end
+    end)
+
+    it('handles noon correctly', function()
+      local noon = make_timestamp(today.year, today.month, today.day, 12, 0, 0)
+      local result = util.format_time(noon)
+
+      assert.matches('^%d%d?:%d%d [AP]M$', result)
+      assert.matches('12:00 PM', result) -- Noon should be 12:00 PM
+    end)
+
+    it('handles date boundary transitions', function()
+      local late_today = make_timestamp(today.year, today.month, today.day, 23, 59, 0)
+      local early_tomorrow = late_today + 120 -- 2 minutes later (next day)
+
+      local late_result = util.format_time(late_today)
+      local early_result = util.format_time(early_tomorrow)
+
+      -- Late today should be time-only
+      assert.matches('^%d%d?:%d%d [AP]M$', late_result)
+
+      -- Early tomorrow behavior depends on whether it's actually tomorrow
+      if os.date('%Y-%m-%d', early_tomorrow) == os.date('%Y-%m-%d') then
+        -- Still today
+        assert.matches('^%d%d?:%d%d [AP]M$', early_result)
+      else
+        -- Actually tomorrow
+        assert.matches('^%d%d? %a%a%a %d%d%d%d %d%d?:%d%d [AP]M$', early_result)
+      end
+    end)
+  end)
+
+  describe('timezone consistency', function()
+    it('uses consistent timezone for date comparison', function()
+      local now = os.time()
+
+      -- Both should use the same local timezone
+      local timestamp_date = os.date('%Y-%m-%d', now)
+      local current_date = os.date('%Y-%m-%d')
+
+      assert.equals(timestamp_date, current_date)
+
+      local result = util.format_time(now)
+      assert.matches('^%d%d?:%d%d [AP]M$', result)
+    end)
+  end)
+end)