SQL Server - converting 13 digit numeric to datetime

Question

How can I convert a 13 digit numeric like 1314637182953 to datetime in SQL Server? Both casting and converting directly give an arithmetic overflow error!

Answer 1

If you don't want to chop off the miliseconds:

CAST(DATEADD(ms, CAST(RIGHT(START_DATE,3) AS smallint), DATEADD(s, START_DATE / 1000, '1970-01-01')) AS datetime2(3))