How to convert NSDate to milliseconds in Objective-C?

The timeIntervalSince1970 will return seconds from 1970. There are other timeIntervalSince methods if needed.

https://developer.apple.com/library/mac/documentation/Cocoa/Reference/Foundation/Classes/NSDate_Class/Reference/Reference.html#//apple_ref/occ/instm/NSDate/timeIntervalSince1970

For reverse conversion, I mean to say from milliseconds to NSDate, refer this stackoverflow article. Convert milliseconds to NSDate

Hope it ll solve your issue.

There is a similar post here and here.

Basically you have get the second form the reference date (1 January 2001, GMT) and multiply it with 1000.

NSTimeInterval seconds = [NSDate timeIntervalSinceReferenceDate];
double milliseconds = seconds*1000;

Cheers!