Hello,
I have a problem to get back my appointment occurrences with the TryParse() method when I use TimeZoneOffset. Here is a procedure I use:
I setup my scheduler for UTC-8:
RadScheduler1.TimeZoneOffset = new TimeSpan(-8, 0, 0);
I enter a new appointment in the schedule: from Wednesday 1 December 2010 08h00PM to 10h00PM, with a recurrence rule: Weekly, Wednesday and Friday, up to 2 occurrences.
This gives me 2 appointments in the scheduler:
Wednesday 1 December 8:00pm
Friday 7 December 8:00pm
The data obtains in the appointment object are in UTC time zone, with values:
Start = {12/2/2010 4:00:00 AM}
End = {12/2/2010 6:00:00 AM}
RecurrenceRule = "DTSTART:20101202T040000Z\r\nDTEND:20101202T060000Z\r\nRRULE:FREQ=WEEKLY;COUNT=2;INTERVAL=1;BYDAY=WE,FR\r\n"
My problem appears when I use the method Telerik.Web.UI.RecurrenceRule.TryParse() on the Recurrence Rule. I obtain a rule with 2 occurrences:
[0] {12/3/2010 4:00:00 AM}
[1] {12/8/2010 4:00:00 AM}
This means in UTC-8:
Thursday 2 December 8:00pm
Friday 8 December 8:00pm
This is not what I scheduled. This appends when the start of the appointment changes of day between local time and UTC time. I think TryParse() cannot restore the occurrence properly because it do not store the time zone in which the rule has been encoded.
I am missing something? Is there another method to get my occurrence from the recurrence rule?
Thank you very much for your help,
Mathieu
5 Answers, 1 is accepted
This is expected, because when you create an appointment for Wednesday, Dec 1, 2010 from 8pm to 10 pm with TimeZoneOffset="-08:00:00", the appointment being saved in UTC falls in the next day which is Thursday Dec 2, 2010. Now, when you parse your weekly rule, RadScheduler takes the next two possible days according the rule which are Friday, Dec 3 and Wednesday, Dec 8.
If you want the occurrences of your parsed recurrence rule to coincide with the actual appointments in RadScheduler, please use the following workaround:
protected void RadScheduler1_AppointmentDataBound(object sender, SchedulerEventArgs e) { if (e.Appointment.RecurrenceState == RecurrenceState.Master) { //Response.Write(e.Appointment.Start+"<br/>"); RecurrenceRule rrule; RecurrenceRule.TryParse(e.Appointment.RecurrenceRule, out rrule); rrule.Range.Start = rrule.Range.Start.Add(RadScheduler1.TimeZoneOffset); foreach (DateTime occurrence in rrule.Occurrences) { Response.Write(occurrence + "<br/>"); } } }Feel free to contact us if you have further questions.
Regards,
Peter
the Telerik team
Rank 1
Indeed I get the correct occurrences days with this solution. However occurrences hours are now in local TimeZone, this is a problem since my application works in UTC TimeZone.
So I used this (ugly) workaround : If we are in case where the scheduler did not set the correct days in the recurrence rule (due to time offset), I correct the rule by shifting the days in the pattern to match what the user of scheduler really chose:
private RecurrenceRule getGoodOccurences(String recurrenceRuleFromScheduler, TimeSpan timeZoneOffset){ // parse occurences with scheduler input Telerik.Web.UI.RecurrenceRule rule; if (!Telerik.Web.UI.RecurrenceRule.TryParse(recurrenceRuleFromScheduler, out rule)) return null; // correct the input if day in system timezone is different from day in site timezone if ((this.Start + timeZoneOffset).Day != this.Start.Day) { RecurrenceDay recurrenceDay = rule.Pattern.DaysOfWeekMask; int recurrenceBits = (int)recurrenceDay; // shift days in a direction, depending of the timezone offset if (timeZoneOffset.Hours < 0) { recurrenceBits = recurrenceBits << 1; recurrenceBits &= ~((int)RecurrenceDay.EveryDay + 1); if ((recurrenceDay & RecurrenceDay.Saturday) == RecurrenceDay.Saturday) recurrenceBits++; } else { recurrenceBits = recurrenceBits >> 1; if ((recurrenceDay & RecurrenceDay.Sunday) == RecurrenceDay.Sunday) recurrenceBits |= (int)RecurrenceDay.Saturday; } // we have the correct days, we can recompute the RecurrenceRule rule.Pattern.DaysOfWeekMask = (RecurrenceDay)recurrenceBits; } return rule;}This code works, but maybe there is a better solution ?
Thank you very much for your time,
Mathieu
Thank you for sharing your findings in the forum. We haven't done an extensive research on how to best handle such cases yet, so I cannot suggest a better solution than what you have already tried. Should I discover any other approaches, I will let you know.
Greetings,
Peter
the Telerik team
Rank 1
what i need exactly is
When i am inserting events with weekly recurrence rule with
startdate = Dec 2nd 2010,
intervel = 2
occurrence = 6
weekly mask = Sunday|Friday|Saturday
it is showing events on
Dec 3rd
Dec 4th
Dec 12th
the above events are wrong . it should show like below events
Dec 3rd
Dec 4th
Dec 5th
Please give me reply ASAP . Thanking you
Thanks & Regards
Shashi....
Which workaround precisely have you tried. Can you send us the code of your implementation?
Regards,
Peter
the Telerik team