Date localization does unexpected things if all you're familiar with is U.S. dates.

date_surprise.m

// iPhone settings: "Denmark" for region and "Buddhist" for calendar.
NSDate* now = [NSDate date];

NSDateFormatter* df = [[NSDateFormatter alloc] init];
df.timeZone = [NSTimeZone timeZoneWithName:@"UTC"];
df.timeStyle = NSDateFormatterMediumStyle;
df.dateStyle = NSDateFormatterShortStyle;

// Date: 30/10/2563 BE, 14.32.18
NSLog(@"Date: %@", [df stringFromDate:now]);

NSISO8601DateFormatter* isoDf = [[NSISO8601DateFormatter alloc] init];
isoDf.formatOptions = NSISO8601DateFormatWithInternetDateTime;

// ISO Date: 2020-10-30T14:32:18Z
NSLog(@"ISO Date: %@", [isoDf stringFromDate:now]);