I face the exact same problem. Here is a screenshot of my calender:
I have multiple timers and each timer triggers a different switch. And all BEGIN-events are not fired on time.
This is my thing -config:
Bridge icalendar:calendar:google “Kalender” [ url=“google-url”, refreshTime=1, username=“username”, password=“password” ]
Thing icalendar:eventfilter:bedroom “Timer-Schlafzimmer-Wecker” (icalendar:calendar:google) [ maxEvents=1, refreshTime=10, datetimeUnit=“DAY”, datetimeStart=0, datetimeEnd=1, datetimeRound=true, textEventField=“SUMMARY”, textEventValue=“Timer-Schlafzimmer-Wecker”, textValueType=“TEXT”]
Thing icalendar:eventfilter:hall “Timer-Flur-Decke” (icalendar:calendar:google) [ maxEvents=1, refreshTime=10, datetimeUnit=“DAY”, datetimeStart=0, datetimeEnd=1, datetimeRound=true, textEventField=“SUMMARY”, textEventValue=“Timer-Flur-Decke”, textValueType=“TEXT”]
Thing icalendar:eventfilter:livingroom “Timer-Wohnzimmer-Deko” (icalendar:calendar:google) [ maxEvents=1, refreshTime=10, datetimeUnit=“DAY”, datetimeStart=0, datetimeEnd=1, datetimeRound=true, textEventField=“SUMMARY”, textEventValue=“Timer-Wohnzimmer-Deko”, textValueType=“TEXT”]
Thing icalendar:eventfilter:blinds “Timer-Jalousie” (icalendar:calendar:google) [ maxEvents=1, refreshTime=10, datetimeUnit=“DAY”, datetimeStart=0, datetimeEnd=1, datetimeRound=true, textEventField=“SUMMARY”, textEventValue=“Timer-Jalousie”, textValueType=“TEXT”]
Thing icalendar:eventfilter:vacation “Timer-Urlaub” (icalendar:calendar:google) [ maxEvents=1, refreshTime=10, datetimeUnit=“DAY”, datetimeStart=0, datetimeEnd=1, datetimeRound=true, textEventField=“SUMMARY”, textEventValue=“Timer-Urlaub”, textValueType=“TEXT”]
Thing icalendar:eventfilter:test “Timer-Test” (icalendar:calendar:google) [ maxEvents=1, refreshTime=1, datetimeUnit=“DAY”, datetimeStart=0, datetimeEnd=1, datetimeRound=true, textEventField=“SUMMARY”, textEventValue=“Timer-Test”, textValueType=“TEXT”]
this is my item config:
DateTime CalDav_Hall_Start “Flur - Beginn [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:hall:result_0#begin” }
DateTime CalDav_Hall_End “Flur - Ende [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:hall:result_0#end” }
DateTime CalDav_Bedroom_Start “Schlafzimmer-Wecker - Beginn [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:bedroom:result_0#begin” }
DateTime CalDav_Bedroom_End “Schlafzimmer-Wecker - Ende [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:bedroom:result_0#end” }
DateTime CalDav_Livingroom_Start “Wohnzimmer-Deko - Beginn [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:livingroom:result_0#begin” }
DateTime CalDav_Livingroom_End “Wohnzimmer-Deko - Ende [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:livingroom:result_0#end” }
DateTime CalDav_Blinds_Start “Jalousie - Beginn [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:blinds:result_0#begin” }
DateTime CalDav_Blinds_End “Jalousie - Ende [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:blinds:result_0#end” }
DateTime CalDav_Vacation_Start “Urlaub - Beginn [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:vacation:result_0#begin” }
DateTime CalDav_Vacation_End “Urlaub - Ende [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:vacation:result_0#end” }
DateTime CalDav_Test_Start “Test - Beginn [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:test:result_0#begin” }
DateTime CalDav_Test_End “Test - Ende [%1$td.%1$tm.%1$tY, %1$tT]” { channel=“icalendar:eventfilter:test:result_0#end” }
is this enough or can I provide more information?