Google Calendar events not showing up on Andriod

Hello Folks,

I have implemented a Google Calendar synchronisation in my DataSnap server. It pushed appointments into the Google Calendar based in an update stamp in the database. All is working fine when looking at the calendar with Google Chrome on a PC.

The problem my customer reports is that the Android apps he is using - aCalendar+ & Google Calendar - sometimes need up to 2 hours to show the new or updated appointments, that are visible instantly on Google Chrome. Even calling a resync manually on the Android phone is not helping.

The customer has many - and I mean MANY - events in his calendar. I checked the Google Calendar API here:

Obviously I don't know what optional parameters the Android apps are using. The parameters updatedMin or maxResults look interesting. I don't know if I need to do something special when adding or updating an event in order to set for example the "last modification time".

My DataSnap server has not been updated in a while, which is why I am using v3.4.0.0 of TMS VCL Cloud Pack. Changes to TAdvGCalendar since v3.4 indicate a "Event StartTime and EndTime TimeZone offset" in v3.8 and "TimeZone Bias was incorrect for specific timezones" in v3.8.3.1.
I am not doing anything special regarding the timezone in my Delphi code. All I do regaring times is:

GCalendarItem.StartTime := qryNewAppointmentDATETIME.AsDateTime;
GCalendarItem.EndTime := IncMinute(qryNewAppointmentDATETIME.AsDateTime, 120);
for a default of 120 minutes events.

Has anyone experienced a similar problem with Google Calendar events
creating via TAdvGCalendar, which need a long time to show up on Android



We are not aware of any issues with submitting events to Google Calendar and we haven't received any similar reports from other users.
AFAIK the API does not support setting the last modification time. This is probably handled automatically by the service.
If the events are available in the browser I can only assume the issue is with the Android app.

Thanks Bart.
By now I believe it is a volume problem. My customer has
so many appointments in his calendar that the Android app tries to
break it up in chunks and does not retrieve all changes at once. After
all the events appear on the aCalendar+, just with a lot of delay. I may
have to take this up with Matthias from Tapir Apps.