diff --git a/usr.bin/at/at.man b/usr.bin/at/at.man
index 19b79d1a5a27..a972af93acfd 100644
--- a/usr.bin/at/at.man
+++ b/usr.bin/at/at.man
@@ -18,7 +18,11 @@
 .Op Fl q Ar queue
 .Op Fl f Ar file
 .Op Fl mldbv
-.Fl t Ar [[CC]YY]MMDDhhmm[.SS]
+.Fl t
+.Sm off
+.Op Oo Ar CC Oc Ar YY
+.Ar MM DD hh mm Op . Ar SS
+.Sm on
 .Nm at
 .Fl c Ar job Op Ar job ...
 .Nm at
@@ -120,7 +124,7 @@ and to run a job at 1am tomorrow, use
 .Pp
 The
 .Nm at
-utility also supports the POSIX time format (see 
+utility also supports the \*[Px] time format (see
 .Fl t
 option).
 .Pp
@@ -221,8 +225,8 @@ Is an alias for
 .Nm atq .
 .It Fl d
 Is an alias for
-.Nm atrm 
-(this option is deprecated; use 
+.Nm atrm
+(this option is deprecated; use
 .Fl r
 instead).
 .It Fl b
@@ -236,14 +240,17 @@ shows the time the job will be executed.
 .It Fl c
 Cat the jobs listed on the command line to standard output.
 .It Fl r
-Remove specified job(s). 
+Remove the specified jobs.
 .It Fl t
-Specify the job time using the POSIX time format.
+Specify the job time using the \*[Px] time format.
 The argument should be in the form
-.Dq [[CC]YY]MMDDhhmm[.SS]
+.Sm off
+.Op Oo Ar CC Oc Ar YY
+.Ar MM DD hh mm Op . Ar SS
+.Sm on
 where each pair of letters represents the following:
 .Pp
-.Bl -tag -width Ds -compact -offset indent
+.Bl -tag -width indent -compact -offset indent
 .It Ar CC
 The first two digits of the year (the century).
 .It Ar YY
@@ -261,13 +268,13 @@ The second of the minute, from 0 to 61.
 .El
 .Pp
 If the
-.Dq CC
+.Ar CC
 and
-.Dq YY
+.Ar YY
 letter pairs are not specified, the values default to the current
 year.
 If the
-.Dq SS
+.Ar SS
 letter pair is not specified, the value defaults to 0.
 .El
 .Sh FILES
@@ -309,7 +316,7 @@ and
 as presently implemented are not suitable when users are competing for
 resources.
 If this is the case, another batch system such as
-.Em nqs 
+.Em nqs
 may be more suitable.
 .Pp
 Specifying a date past 2038 may not work on some systems.
@@ -318,5 +325,5 @@ At was mostly written by
 .An Thomas Koenig Aq ig25@rz.uni-karlsruhe.de .
 The time parsing routines are by
 .An David Parsons Aq orc@pell.chi.il.us ,
-with minor enhancements by 
+with minor enhancements by
 .An Joe Halpin Aq joe.halpin@attbi.com .