milliseconds UTC from discrete year, month, day, hour, minute, second
Hello, Can someone should me how to calculate the milliseconds since jan 1, 1970 in UTC, given separate variables holding the year, month,day,hour,minute and seconds? Thanks,
On 11/21/2013 08:30 PM, Victor Yankee wrote:
Can someone should me how to calculate the milliseconds since jan 1, 1970 in UTC, given separate variables holding the year, month,day,hour,minute and seconds?
std::mktime(your_time) * 1000
On Nov 22, 2013, at 5:59 AM, Bjorn Reese
On 11/21/2013 08:30 PM, Victor Yankee wrote:
Can someone should me how to calculate the milliseconds since jan 1, 1970 in UTC, given separate variables holding the year, month,day,hour,minute and seconds?
std::mktime(your_time) * 1000
The precision of time_t (the return of mktime) is implementation defined. Additionally it should be noted that the input to mktime is in the local time zone, not UTC. And traditionally this solution won't take leap seconds into account (though it certainly might). The same question was asked on SO, and I've provided an answer there: http://stackoverflow.com/a/20149882/576911 There's two versions: 1. A really simple solution that neglects leap seconds. 2. A slightly more complicated solution that isn't fully coded in the answer that will take leap seconds into account. The answers don't depend on implementation-defined properties, and can use either boost::chrono, or std::chrono to simplify the duration arithmetic. No explicit conversion factors are used, except to specify that there are 24 hours in a day. Howard
participants (3)
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Bjorn Reese -
Howard Hinnant -
Victor Yankee