Better preserve timezones in ical

lib/ice_cube/builders/ical_builder.rb

@@ -35,10 +35,22 @@ def self.ical_utc_format(time)
 
     def self.ical_format(time, force_utc)
       time = time.dup.utc if force_utc
+
+      # Keep timezone. strftime will serializer short versions of time zone (eg. EEST),
+      # which are not reversivible, as there are many repeated abbreviated zones. This will result in
+      # issues in parsing
+      if time.respond_to?(:time_zone)
+        tz_id = time.time_zone.name
+        return ";TZID=#{tz_id}:#{IceCube::I18n.l(time, format: "%Y%m%dT%H%M%S")}" # local time specified"
+      end
+
       if time.utc?
         ":#{IceCube::I18n.l(time, format: "%Y%m%dT%H%M%SZ")}" # utc time
       else
-        ";TZID=#{IceCube::I18n.l(time, format: "%Z:%Y%m%dT%H%M%S")}" # local time specified
+        # Convert to UTC as TZID=+xxxx format is not recognized by JS libraries
+        warn "IceCube: Time object does not have timezone info. Assuming UTC: #{caller(1..1).first}"
+        utc_time = time.dup.utc
+        ":#{IceCube::I18n.l(utc_time, format: "%Y%m%dT%H%M%SZ")}" # converted to utc time
       end
     end
 

lib/ice_cube/parsers/ical_parser.rb

@@ -4,18 +4,25 @@ def self.schedule_from_ical(ical_string, options = {})
       data = {}
       ical_string.each_line do |line|
         (property, value) = line.split(":")
-        (property, _tzid) = property.split(";")
+        (property, tzid_param) = property.split(";")
+
+        # Extract TZID if present
+        tzid = nil
+        if tzid_param && tzid_param.start_with?("TZID=")
+          tzid = tzid_param[5..-1] # Remove "TZID=" prefix
+        end
+
         case property
         when "DTSTART"
-          data[:start_time] = TimeUtil.deserialize_time(value)
+          data[:start_time] = deserialize_time_with_tzid(value, tzid)
         when "DTEND"
-          data[:end_time] = TimeUtil.deserialize_time(value)
+          data[:end_time] = deserialize_time_with_tzid(value, tzid)
         when "RDATE"
           data[:rtimes] ||= []
-          data[:rtimes] += value.split(",").map { |v| TimeUtil.deserialize_time(v) }
+          data[:rtimes] += value.split(",").map { |v| deserialize_time_with_tzid(v, tzid) }
         when "EXDATE"
           data[:extimes] ||= []
-          data[:extimes] += value.split(",").map { |v| TimeUtil.deserialize_time(v) }
+          data[:extimes] += value.split(",").map { |v| deserialize_time_with_tzid(v, tzid) }
         when "DURATION"
           data[:duration] # FIXME
         when "RRULE"
@@ -26,6 +33,22 @@ def self.schedule_from_ical(ical_string, options = {})
       Schedule.from_hash data
     end
 
+    def self.deserialize_time_with_tzid(time_value, tzid)
+      if tzid.nil? || tzid.empty?
+        # No TZID, use standard deserialization
+        TimeUtil.deserialize_time(time_value)
+      else
+        # TZID is a timezone name - Assume it's a valid timezone in a try-catch block
+        begin
+          TimeUtil.deserialize_time({time: time_value, zone: tzid})
+        rescue ArgumentError
+          # If the timezone is invalid, fall back to standard deserialization
+          # Perhaps we want to log this?
+          TimeUtil.deserialize_time(time_value)
+        end
+      end
+    end
+
     def self.rule_from_ical(ical)
       raise ArgumentError, "empty ical rule" if ical.nil?
 

lib/ice_cube/time_util.rb

@@ -87,7 +87,8 @@ def self.serialize_time(time)
       case time
       when Time, Date
         if time.respond_to?(:time_zone)
-          {time: time.utc, zone: time.time_zone.name}
+          # avoid .utc as it changes the object timezone
+          {time: time.getutc, zone: time.time_zone.name}
         else
           time
         end

spec/examples/from_ical_spec.rb

@@ -110,7 +110,7 @@ module IceCube
     ICAL
 
     ical_string_with_multiple_rules = <<-ICAL.gsub(/^\s*/, "")
-  DTSTART;TZID=CDT:20151005T195541
+  DTSTART;TZID=America/Chicago:20151005T195541
   RRULE:FREQ=WEEKLY;BYDAY=MO,TU
   RRULE:FREQ=WEEKLY;INTERVAL=2;WKST=SU;BYDAY=FR
     ICAL

spec/examples/to_ical_spec.rb

@@ -97,7 +97,7 @@
   it "should be able to serialize a base schedule to ical in local time" do
     Time.zone = "Eastern Time (US & Canada)"
     schedule = IceCube::Schedule.new(Time.zone.local(2010, 5, 10, 9, 0, 0))
-    expect(schedule.to_ical).to eq("DTSTART;TZID=EDT:20100510T090000")
+    expect(schedule.to_ical).to eq("DTSTART;TZID=Eastern Time (US & Canada):20100510T090000")
   end
 
   it "should be able to serialize a base schedule to ical in UTC time" do
@@ -110,7 +110,7 @@
     schedule = IceCube::Schedule.new(Time.zone.local(2010, 5, 10, 9, 0, 0))
     schedule.add_recurrence_rule IceCube::Rule.weekly
     # test equality
-    expectation = "DTSTART;TZID=PDT:20100510T090000\n"
+    expectation = "DTSTART;TZID=Pacific Time (US & Canada):20100510T090000\n"
     expectation << "RRULE:FREQ=WEEKLY"
     expect(schedule.to_ical).to eq(expectation)
   end
@@ -120,7 +120,7 @@
     schedule = IceCube::Schedule.new(Time.zone.local(2010, 10, 20, 4, 30, 0))
     schedule.add_recurrence_rule IceCube::Rule.weekly.day_of_week(monday: [2, -1])
     schedule.add_recurrence_rule IceCube::Rule.hourly
-    expectation = "DTSTART;TZID=EDT:20101020T043000\n"
+    expectation = "DTSTART;TZID=Eastern Time (US & Canada):20101020T043000\n"
     expectation << "RRULE:FREQ=WEEKLY;BYDAY=2MO,-1MO\n"
     expectation << "RRULE:FREQ=HOURLY"
     expect(schedule.to_ical).to eq(expectation)
@@ -131,7 +131,7 @@
     schedule = IceCube::Schedule.new(Time.zone.local(2010, 5, 10, 9, 0, 0))
     schedule.add_exception_rule IceCube::Rule.weekly
     # test equality
-    expectation = "DTSTART;TZID=PDT:20100510T090000\n"
+    expectation = "DTSTART;TZID=Pacific Time (US & Canada):20100510T090000\n"
     expectation << "EXRULE:FREQ=WEEKLY"
     expect(schedule.to_ical).to eq(expectation)
   end
@@ -141,7 +141,7 @@
     schedule = IceCube::Schedule.new(Time.zone.local(2010, 10, 20, 4, 30, 0))
     schedule.add_exception_rule IceCube::Rule.weekly.day_of_week(monday: [2, -1])
     schedule.add_exception_rule IceCube::Rule.hourly
-    expectation = "DTSTART;TZID=EDT:20101020T043000\n"
+    expectation = "DTSTART;TZID=Eastern Time (US & Canada):20101020T043000\n"
     expectation << "EXRULE:FREQ=WEEKLY;BYDAY=2MO,-1MO\n"
     expectation << "EXRULE:FREQ=HOURLY"
     expect(schedule.to_ical).to eq(expectation)
@@ -192,10 +192,10 @@
     expect(schedule.duration).to eq(3600)
   end
 
-  it "should default to to_ical using local time" do
+  it "should default to to_ical using UTC when there is no timezone info" do
     time = Time.now
-    schedule = IceCube::Schedule.new(Time.now)
-    expect(schedule.to_ical).to eq("DTSTART;TZID=#{time.zone}:#{time.strftime("%Y%m%dT%H%M%S")}") # default false
+    schedule = IceCube::Schedule.new(time)
+    expect(schedule.to_ical).to eq("DTSTART:#{time.utc.strftime("%Y%m%dT%H%M%S")}Z") # converts local to UTC
   end
 
   it "should not have an rtime that duplicates start time" do
@@ -207,10 +207,10 @@
 
   it "should be able to receive a to_ical in utc time" do
     time = Time.now
-    schedule = IceCube::Schedule.new(Time.now)
-    expect(schedule.to_ical).to eq("DTSTART;TZID=#{time.zone}:#{time.strftime("%Y%m%dT%H%M%S")}") # default false
-    expect(schedule.to_ical(false)).to eq("DTSTART;TZID=#{time.zone}:#{time.strftime("%Y%m%dT%H%M%S")}")
-    expect(schedule.to_ical(true)).to eq("DTSTART:#{time.utc.strftime("%Y%m%dT%H%M%S")}Z")
+    schedule = IceCube::Schedule.new(time)
+    expect(schedule.to_ical).to eq("DTSTART:#{time.utc.strftime("%Y%m%dT%H%M%S")}Z") # converts local to UTC
+    expect(schedule.to_ical(false)).to eq("DTSTART:#{time.utc.strftime("%Y%m%dT%H%M%S")}Z") # still converts local to UTC
+    expect(schedule.to_ical(true)).to eq("DTSTART:#{time.utc.strftime("%Y%m%dT%H%M%S")}Z") # force UTC
   end
 
   it "should be able to serialize to ical with an until date" do