如何将1970/01/01 00:00:00以来的秒数转换为时间？

andy988

I have a int value represents the seconds from 1970-01-01 00:00:00，now I want to convert it to datetime format。
C++ can implements this function , 'print dateadd(ss, intvalue, '1970-01-01 00:00:00')' in sql server can resolve this problem also , but is there a simple method can do same thing in sybase sql ?