1 of the month, yielding the last day of the previous month.
.PP
If the interpretation of the groups yields an impossible time because
a Daylight Saving Time change skips over that time, or an ambiguous
time because a Daylight Saving Time change skips back so that the clock
observes the given time twice, and no time zone specifier (\fB%z\fR
or \fB%Z\fR) is present in the format, the time is interpreted as
if the clock had not changed. 
if the clock had not changed.
.SH "FORMAT GROUPS"
.PP
The following format groups are recognized by the \fBclock scan\fR and
\fBclock format\fR commands.
.TP
\fB%a\fR
On output, receives an abbreviation (\fIe.g.,\fR \fBMon\fR) for the day