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256-week LeapSecond bug

The Wayback Machine - https://web.archive.org/web/20160304002759/http://www.leapsecond.com/notes/leapsec256.htm

Yes, there was a leap second bug today. Not with GPS itself; but with several models of GPS timing receivers.

Following is a SCPI trace from a HP 59551A SmartClock; no bugs here.

scpi > syst:date?;time?
+2003,+11,+27;+23,+59,+56
scpi > syst:date?;time?
+2003,+11,+27;+23,+59,+57
scpi > syst:date?;time?
+2003,+11,+27;+23,+59,+58
scpi > syst:date?;time?
+2003,+11,+27;+23,+59,+59
scpi > syst:date?;time?
+2003,+11,+28;+0,+0,+0
scpi > syst:date?;time?
+2003,+11,+28;+0,+0,+1
scpi > syst:date?;time?
+2003,+11,+28;+0,+0,+2
scpi > syst:date?;time?
+2003,+11,+28;+0,+0,+3

But as predicted, the Motorola Oncore VP receiver has the bug! Here is what I first saw, using LIST on the raw log of @@Bl and 1 Hz @@Ba messages:

In the hex trace note that 11/27/2003 23:59:59 in hexadecimal is 0B/1B/07D3 17:3B:3B and 11/28/2003 00:00:00 in hexadecimal is 0B/1C/07D3 00:00:00:

Here all the @@Ba position messages around UTC midnight have been partially decoded, showing the date/time:

The previous Motorola announcement predicted the incorrect date. But the very incorrect time is a surprise.

We all understood why Y2K was a problem for some software and with some reading you can understand why many old GPS receivers stopped working at the August 21, 1999 WNRO (week number roll-over) event. But this one really takes the cake: everyone's favorite GPS timing receiver, the Motorola Oncore VP, will have a short hiccup on November 27, 2003. Why? Because it's been too long since the last leap second!