Android google calendar deleting future instances of recurring event -

i'm trying delete future instances of google calendar recurring (repeated) event pro-grammatically using content resolver.

and have updated rrule of event , example if want delete future instances of event starting date 11/11/2016 edit rrule string so:

 freq=daily;until=20161111;wkst=su  

however , when viewing google calendar application find no changes , find event color has changed black color.

some notes keep in mind:

1- i'm using third party library : https://github.com/everythingme/easy-content-providers

calendarprovider calendarprovider = new calendarprovider(context); event event = calendarprovider.getevent(eventid); event.rrule = "freq=daily;until=20161111;wkst=su"; calendarprovider.update(event); 

and functionalities in library seem work fine.

2- while reading pro-grammatically recurring events have specific until date in it's rrule , have realized field in google event called "lastdate" updated 1 hour later after until value ,so have update field while updating until value in rrule?

the problem library ,

calendarprovider.update(event); 

does not seems work event fields!