Number of seconds from 1st January 1900 to start of Unix epoch

Question

I need to report a time in seconds since 1st January 1900. I have the number of seconds since the start of the Unix epoch.

Can anybody point me to a definitive refe

Answer 1

According to the Time protocol in RFC 868 it is 2208988800L.

The Time

The time is the number of seconds since 00:00 (midnight) 1 January 1900 GMT, such that the time 1 is 12:00:01 am on 1 January 1900 GMT; this base will serve until the year 2036.

For example:

the time 2,208,988,800 corresponds to 00:00 1 Jan 1970 GMT,

         2,398,291,200 corresponds to 00:00  1 Jan 1976 GMT,

         2,524,521,600 corresponds to 00:00  1 Jan 1980 GMT,

         2,629,584,000 corresponds to 00:00  1 May 1983 GMT,

    and -1,297,728,000 corresponds to 00:00 17 Nov 1858 GMT.

Answer 2

70 years = 2,208,988,800 seconds, 01-01-1900 00:00 to 01:01-1970 00:00