How to decode some number into timeDate?

Question

This question is sequel of this one.

So any idea how to decode this number 5252235562500 into date and time 19.11.2010 15:43 ? I have more pairs like this and I\'m t

Answer 1

When you're trying to decode a foreign time format, you need two known times. Take the difference between them and see what it equates to - second, milliseconds, days, there aren't too many possibilities. Now that you have the basic time unit, you can work with one of the times and see what the origin time is.

I just had to do this last week. I had two dates:

2009-07-15 15:29:12  1247689752
2009-07-17 08:27:55  1247837275

There are lots of ways to get the difference between two dates. The easiest is probably Excel, which will display the difference in days; in this case 1.70744213. The difference between the two representations is 147523. Multiplying the number of days by the number of seconds in a day (24*60*60) also resulted in 147523, so now I know that the date is the number of seconds elapsed from some starting date.

To get the starting date, I subtract a date from itself. Again this is trivial in Excel: divide the date number by the number of seconds in a day, then subtract. In my case it comes up 1969-12-31 19:00. This seems a little odd, but I realize that my time zone is 5 hours off of UTC in the summer. This tells me that the time value is in UTC, and represents the number of seconds since 1970-01-01.