1 files changed, 29 insertions, 5 deletions

diff --git a/bin/man1/when.1 b/bin/man1/when.1
index 0b473573..3f2735f7 100644
--- a/bin/man1/when.1
+++ b/bin/man1/when.1
@@ -1,4 +1,4 @@
-.Dd July 24, 2019
+.Dd September 19, 2022
 .Dt WHEN 1
 .Os
 .
@@ -9,6 +9,8 @@
 .Sh SYNOPSIS
 .Nm
 .Op Ar expr
+.Nm
+.Cm -
 .
 .Sh DESCRIPTION
 .Nm
@@ -18,24 +20,32 @@ If no
 is given,
 expressions are read
 from standard input.
+If
+.Cm -
+is given,
+the intervals between each named date
+and today are printed.
 .
 .Pp
 The grammar is as follows:
 .Bl -tag -width Ds
 .It Sy \&.
 Today's date.
+The empty expression is equivalent.
+.
+.It Ar name Op Sy = Ar date
+A named date.
+Names are alphanumeric including underscores.
 .
 .It Ar month Ar date Op Ar year
 A full date,
 or a date in the current year.
-.Ar month
-must be at least three letters.
+Months can be abbreviated to three letters.
 .
 .It Ar day
 A day of the week
 in the current week.
-.Ar day
-must be at least three letters.
+Days can be abbreviated to three letters.
 .
 .It Sy < Ar date
 The date one week before.
@@ -65,6 +75,14 @@ A number of months.
 A number of years.
 .El
 .
+.Sh FILES
+The file
+.Pa $XDG_CONFIG_HOME/when/dates
+or
+.Pa ~/.config/when/dates
+is read before any other expressions,
+if it exists.
+.
 .Sh EXAMPLES
 .Bl -tag -width "Dec 25 - ."
 .It Ic Dec 25 - \&.
@@ -74,3 +92,9 @@ The date next Friday.
 .It Ic \&. + 2w
 Your last day at work.
 .El
+.Pp
+Checking a milestone:
+.Bd -literal -offset indent
+$ echo 'hrt = oct 15 2021' >> ~/.config/when/dates
+$ when -hrt
+.Ed