import datetime
STD_TIME = datetime.datetime(1970, 1, 1, 0, 0)
st_tm = datetime.datetime(y, M, d, h, m)
dt = (dst_tm - STD_TM).total_seconds()
sql = 'select DATEADD(SECOND, {0}, dt, CAST('1970-01-01 00:00:00' AS datetime))'.format(dt)
# etc. options
處理字符串cast到datetime時出現的out of range的問題