Question

I am developing one application in that I want to find application installation date on my device and when update happen that date and time as programmatically.

Answer 1

Not sure if you can find an application installation date but you could save the current date when the application is first ran. Something like this should do the trick

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
if (![prefs objectForKey:@"installation_date"]) {
        NSDate *now = [NSDate date];
        [prefs setObject:now forKey:@"installation_date"];
}

(This code is untested)