Q: my agenda of the macbook air do not synchronige with my iphone ?

Hi erikfromweesp,

I understand you are experiencing issues syncing your iCloud data. I'm unclear if you are having trouble with your calendar data or reminders. I've included links to two articles that may help you find a solution: 

Get help using Reminders in iCloud - Apple Support

Get help using iCloud Calendar - Apple Support

Thank you for contributing to Apple Support Communities.

Take care,

Bobby_D