Year 2000 compliance and Leap Seconds

Because of the use of the MJD clock, the ZY software is not subject to Year 2000 problems[18]. The hardware it runs on, however, may possibly be affected. The hardware in current use has been tested for Y2K compliance and no problems were found. The ZY software does make the assumption that there are 86400 seconds in a day, and because once the time is set the clock is maintained by a 1PPS IRQ, any leap second appearing in the IRIG-B signal will not be recorded. Later versions of the ZY will address this problem. For now, it is sufficient to reset the ZY clock when a leap second occurs (see STI).