System.currentTimeMillis() does give you the number of milliseconds since January 1, 1970 00:00:00 UTC. The reason you see local times might be because you convert a Date instance to a string before using it. You can use DateFormats to convert Dates to Strings in any timezone: DateFormat df = DateFormat.getTimeInstance(); df.setTimeZone(TimeZone.getTimeZone(“gmt”)); String gmtTime = df.format(new … Read more
In Python 3.x, local timezone can be figured out like this: >>> import datetime >>> print(datetime.datetime.now(datetime.timezone.utc).astimezone().tzinfo) AEST It’s a tricky use of datetime‘s code . For python < 3.6, you’ll need >>> import datetime >>> print(datetime.datetime.now(datetime.timezone(datetime.timedelta(0))).astimezone().tzinfo) AEST
The .NET framework already has classes and methods available to convert DateTimes between different time zones. Have a look at the ConvertTime methods of the TimeZoneInfo class. Edit: When you get the time to put into the database, assuming it was created with correct time zone information you can easily convert to UTC: DateTime utcTime … Read more
It has a set timezone method: SimpleDateFormat simpleDateFormat = new SimpleDateFormat(“yyyy-MM-dd HH:mm:ss”); simpleDateFormat.setTimeZone(TimeZone.getTimeZone(“UTC”)); Date myDate = simpleDateFormat.parse(rawQuestion.getString(“AskDateTime”)); all done!
In older browsers, you can write a function that will parse the string for you. This one creates a Date.fromISO method- if the browser can natively get the correct date from an ISO string, the native method is used. Some browsers got it partly right, but returned the wrong timezone, so just checking for NaN … Read more
GMT does not adjust for Daylight saving time (DST). You can hear it from the horse’s mouth on this web site. Add this line of code to see the source of the problem: Console.WriteLine(TimeZoneInfo.FindSystemTimeZoneById(“GMT Standard Time”).SupportsDaylightSavingTime); Output: True. This is not a .NET problem, it is Windows messing up. The registry key that TimeZoneInfo uses … Read more
Excuse me for mentioning it, I suspect that there is no problem in your code, there’s only confusion. If you think the old Date class is behaving confusingly, allow me to be the first of many to agree with you. The good and sound solution to this problem is you stop using Date and start … Read more
Maybe the “K” format specifier would be of some use. This is the only one that seems to mention the use of capital “Z”. “Z” is kind of a unique case for DateTimes. The literal “Z” is actually part of the ISO 8601 datetime standard for UTC times. When “Z” (Zulu) is tacked on the … Read more
[NSDate date]; You may want to create a category that does something like this: -(NSString *)getUTCFormateDate:(NSDate *)localDate { NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; NSTimeZone *timeZone = [NSTimeZone timeZoneWithName:@”UTC”]; [dateFormatter setTimeZone:timeZone]; [dateFormatter setDateFormat:@”yyyy-MM-dd HH:mm:ss”]; NSString *dateString = [dateFormatter stringFromDate:localDate]; [dateFormatter release]; return dateString; }
Hugo’s answer is mostly correct, but I’ll add a few key points: When you’re storing the customer’s time zone, do NOT store a numerical offset. As others have pointed out, the offset from UTC is only for a single point in time, and can easily change for DST and for other reasons. Instead, you should … Read more