Reputation: 1444
I am having a problem with calculating time difference between two timeZones.
If I am at location A I know the latitude and longitude and the current time. I go to location B I know the latitude and longitude and the current time.
How to calculate the time difference between the two current points .. (in UTC)
Upvotes: 3
Views: 5164
Reputation: 20136
Firstly get a database or library that converts lat/long to get the country and state/province. Then use the NSTimeZone class to retrieve the timezone for a particular country. You can purchase such databases from many sites, ie: http://www.ip2location.com/
To do the actual conversion you would do something like this:
NSTimeZone *sourceTimeZone =
[NSTimeZone timeZoneWithAbbreviation: @"GMT"];
NSTimeZone *destinationTimeZone =
[NSTimeZone timeZoneWithAbbreviation: @"EST"];
NSInteger sourceSeconds =
[sourceTimeZone secondsFromGMTForDate:date];
NSInteger destinationSeconds =
[destinationTimeZone secondsFromGMTForDate:date];
NSTimeInterval interval = destinationSeconds - sourceSeconds;
Upvotes: 4