def u2nt_time(epoch):
    """
    Convert UNIX epoch time to NT filestamp
    quoting from spec: The FILETIME structure is a 64-bit value 
    that represents the number of 100-nanosecond intervals that
    have elapsed since January 1, 1601, Coordinated Universal Time
    """
    return int(epoch*10000000.0)+116444736000000000