tzset.3: Add some clarifying remarks to discussion of Julian day formats

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

diff --git a/man3/tzset.3 b/man3/tzset.3
index a536764294d246a41a71ddc6b711e0c957b30362..af1aa2e25b44fdd436122fa307c19a6b3c6b1201 100644 (file)
--- a/man3/tzset.3
+++ b/man3/tzset.3
@@ -131,10 +131,12 @@ These fields may have the following formats:
 .TP
 J\fIn\fP
 This specifies the Julian day with \fIn\fP between 1 and 365.
-February 29 is never counted even in leap years.
+Leap days are not counted.
+In this format, February 29 can't be represented;
+February 28 is day 59, and March 1 is always day 60.
 .TP
 .I n
-This specifies the Julian day with \fIn\fP between 0 and 365.
+This specifies the zero-based Julian day with \fIn\fP between 0 and 365.
 February 29 is counted in leap years.
 .TP
 M\fIm\fP.\fIw\fP.\fId\fP