[time-nuts] TBolt: UTC PPS

[Tom Van Baak]

Hal,

The words "insert a pulse" is what causes the confusion in
conjunction with leap seconds. There is no extra or missing
pulse; no double pulse, no early or delayed pulse.

The 1PPS output continues to give a pulse at a 1 Hz rate
regardless if there is leap second or not. There is never
any ambiguity with TAI or UTC with respect to the pulses
themselves.

The confusion with terminology arises from the fact that the
implicit or explicit time-of-day string associated with a UTC
time scale does its funny thing around a leap second. If
there is a negative leap second the "23:59:59" label is
missing. If there is a positive leap second the "23"59"60"
is present. You'll also see some GPS receivers or timing
systems use the unofficial trick of labeling "23:59:59" or
"00:00:00" twice rather than using "23:59:60". No matter
how it's done, it's just the label. The pulses still come once
a second. Does that help clarify the situation?

/tvb