iPhone - what is the difference between NSWeekCalendarUnit and NSWeekdayCalendarUnit?

Question

I am trying to set a repeatingInterval of a UILocalNotification using these values but, as always, Apple docs are vague as hell.

Any clues?

thanks.

Answer 1

Maybe look at this blog I just found about the subject?

AFAIK, NSCalendarUnits are primarely used to split a date or timeInterval into date components (NSDateComponents), to extract the weekday of a date, the year of the date, the hour component of a time, and so on.

In this context:

• the NSWeekCalendarUnit of a date correspond to the week index in the year (from 1st to 52nd week - or 53rd for years with 53 weeks)
• NSWeekdayCalendarUnit corresponds to the day in the week (from Mon to Sun)
• NSDayCalendarUnit corresponds to the day in the year (from 1 to 365)

When using the NSCalendarUnit type with repeatingInterval, the UILocalNotification will be triggered when the corresponding unit changes:

• NSWeekCalendarUnit will trigger the notification every week (every 7 days)
• NSWeekdayCalendarUnit will trigger the notification "every weekday", which corresponds to the same thing here as NSDayCalendarUnit which corresponds to "every day" in the context of a repeatingInterval.