UnixTime
UnixTime[] gives the total number of seconds since the beginning of January 1, 1970, in the GMT time zone.
UnixTime[{y,m,d,h,m,s}] gives the Unix time specification corresponding to a date list.
UnixTime[date] gives the Unix time specification corresponding to a DateObject.
UnixTime["string"] gives the Unix time specification corresponding to a date string.
UnixTime[{"string",{e1,e2,…}}] takes the date string to contain the elements "ei".
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