Creating a repeating end of month event in Google Calendar


Simply create an ICS file and import it into Google Calendar:

BEGIN:VCALENDAR  
VERSION:2.0  
BEGIN:VEVENT  
RRULE:FREQ=MONTHLY;INTERVAL=1;BYSETPOS=-1;BYDAY=SU,MO,TU,WE,TH,FR,SA  
SUMMARY:Timesheets  
DTSTART:20240930T110000Z  
DTEND:20240930T110000Z  
SEQUENCE:0  
DESCRIPTION:Timesheets and Invoices  
END:VEVENT  
END:VCALENDAR