CODEWITHSUNDEEP
objective-ciosgeolocationnsdate
chewy
chewy

Reputation: 8267

convert one nsdate to the time in a specific country

Assuming I have a point in time, represented by

NSDate* now = [NSDate date];

for example: 2012-11-07 13:44:55 +0000 (the local time of the device)

I also have an array of countries each country has a name, and geo coordinates (log,lat)

for example: England,51.5, -0.116667

Q: how would one calculate and convert the above date-time into the current equivalent time in a specific country?

(As a side note, I rather have something local and not calling external API)

Upvotes: 2

Views: 1076

Answers (1)

Breakpoint
Breakpoint

Reputation: 1541

Get a list of time zones available by,

[NSTimeZone abbreviationDictionary]

This would return something of this sort,

EST = "America/New_York";
GMT = GMT;
GST = "Asia/Dubai";
HKT = "Asia/Hong_Kong";
HST = "Pacific/Honolulu";
ICT = "Asia/Bangkok";
IRST = "Asia/Tehran";
IST = "Asia/Calcutta";
JST = "Asia/Tokyo";
KST = "Asia/Seoul";
MDT = "America/Denver";
MSD = "Europe/Moscow";
MSK = "Europe/Moscow";

Now use this time zone abbreviation key, say MSD for Moscow, to get the number of seconds that is offset in Moscow's time zone from the GMT.

NSInteger no_of_seconds = [[NSTimeZone timeZoneWithAbbreviation:@"MSD"] secondsFromGMT];

The 'no_of_seconds' can now be added to the current date to get the date of the desired location, in this case Moscow,

[NSDate dateWithTimeIntervalSinceNow:no_of_seconds]

Upvotes: 3

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