Description: NTP Leap Indicator.  This is a two-bit code 
warning of an impending leap second to be inserted
into the NTP timescale.  The bits are set before
23:59 on the day of insertion and reset after 00:00
on the following day.  This causes the number of
seconds (rollover interval) in the day of insertion
to be increased or decreased by one.  In the case
of primary servers the bits are set by operator 
intervention, while in the case of secondary servers
the bits are set by the protocol.  The two bits, 
bit 0 and bit 1, respectively, are coded as follows:
===================================================
00      no warning
01      last minute has 61 seconds
10      last minute has 59 seconds
11      alarm condition(clock not synchronized)
===================================================
In all except the alarm condition(11), NTP itself
does nothing with these bits, except pass them on to
the time-conversion routines that are not part of
NTP.  The alarm condition occurs when, for whatever
reason, the local clock is not synchronized, such 
as when first coming up or after an extended period
when no primary reference source is available.