How do I configure mutt to display the date header in my local time zone in the pager?

Question

When I view a message in the pager mutt displays the time in the Date header in UTC rather than my local time zone. The index view displays the local time correctly. I found this old mailing list post that describes how to get the local time to display in the status bar at the bottom of the screen, but this still doesn't "fix" the time in the Date header at the top of the screen. Is there any way to get the pager to convert the Date header time to local time?

Solution 1

In your .muttrc add the following line:

set display_filter="exec sed -r \"s/^Date:\\s*(([F-Wa-u]{3},\\s*)?[[:digit:]]{1,2}\\s+[A-Sa-y]{3}\\s+[[:digit:]]{4}\\s+[[:digit:]]{1,2}:[[:digit:]]{1,2}(:[[:digit:]]{1,2})?\\s+[+-][[:digit:]]{4})/date +'Date: %a, %d %b %Y %H:%M:%S %z' -d '\\1'/e\""

This will change the Date: header in the message (for display only) to your local timezone if the header contained a valid RFC formatted date. If the provided date format was incorrect (we are dealing with untrusted user input after all) it will be preserved. To combat a possible attempt to inject the shell code through the header the sed pattern implements a whitelist based on RFC 5322 (this RFC defines the format of the Date: field).

Note that mutt limits the command line to be no more than 255 character long, hence I optimised the original sed command that had stricter whitelist to fit into 255 bytes. If you plan to do other things with the message, then the full sed command you can put in a script is:

sed -r "s/^Date:\s*(((Mon|Tue|Wed|Thu|Fri|Sat|Sun),\s*)?[[:digit:]]{1,2}\s+(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)\s+[[:digit:]]{4}\s+[[:digit:]]{1,2}:[[:digit:]]{1,2}(:[[:digit:]]{1,2})?\s+[+-][[:digit:]]{4})/date +'Date: %a, %d %b %Y %H:%M:%S %z' -d '\1'/e"

Solution 2

The formatting in the index is controlled by the index_format setting -- it's generated by mutt. The Date header isn't controlled by mutt, it's a header included with the message that just gets displayed. If it shows UTC time it's because the sending server decided to use UTC when generating the header. The only way to change it is to actually change the message itself, either when you receive it or when you view it.

Changing it as it comes in means adding a filter to your mail delivery agent, but it needs to be sophisticated enough to parse the existing Date header and rewrite it. It's almost certainly better to just have mutt reformat the message when you look at it. You can set the display_filter property to an executable file, and it will pipe any message you open through the executable before displaying it.

You'll need to write a program or shell script that reads each line of the message and replaces the one with the Date header, or find an existing script (there's one here that might work, although it doesn't seem like it should really be necessary to involve a temporary file)

Solution 3

http://www.mail-archive.com/[email protected]/msg44341.html

This suggests using the 'pager_format', to make it show the letter date in the local timezone:

set pager_format="%4C %Z %[!%b %e at %I:%M %p] %.20n %s%* -- (%P)"

Solution 4

Obligatory Perl solution that preserves the "Date" header while adding an extra "Local-Date" header to contain the localtime version:

#!/usr/bin/perl -n

use Date::Parse;
use POSIX;
use strict;

if (/^Date: (.*)$/) {
    my $datestr = $1;
    my $date = strftime ("%a, %d %b %Y %H:%M:%S",
                         localtime (str2time ($datestr)));
    print "Local-Date: $date\n";
}

print;

Solution 5

Taking Gilles' advice, here's a version that uses a temp file and formail.

#!/bin/bash
TMPFILE=$(mktemp)

# save the message to a file
cat - >"$TMPFILE"
# extract the date header
DATE=$( formail -xDate: < "$TMPFILE" )
# convert to the current timezone (defined by TZ)
DATE=$( date -R -d "$DATE" )
# output the modified message
echo "Date: $DATE"
formail -fI Date < "$TMPFILE"
# clean up
rm -f "$TMPFILE"

View more solutions

Comments

[Gilles 'SO- stop being evil']

Parsing emails is pretty tricky. I recommend using a dedicated tool like formail (part of the procmail package) or reformail (part of maildrop) to extract the existing Date: header and put a new one in place. Take care of edge cases such as a missing or malformatted Date: header.

[Phil]

This works very well, also for index_format.

[Janus Troelsen]

how do you invoke this?

[galaxy]

This is susceptible to code injection attacks through a malformed Date: header -- if you go into a subshell you need to validate/sanitise the input.

[galaxy]

The commented line is susceptible to code injection attacks through a malformed Date: header -- if you go into a subshell you need to validate/sanitise the input, otherwise the script is OK from the security standpoint. However, it is quite heavy for a script that runs on every message you browse.

[Philipp L.]

Is there a possibility to make that work on macOS? I would like to include that in my filter.sed file. Thanks!

[galaxy]

There is not, unless you are using GNU sed (e.g. via Homebrew) -- the above sed commands rely on the e modifier to the s command. That modifier is a GNU extension and macOS'es sed is the BSD one.

[Pankaj Jangid]

Answer by @viric is good. No need to change message via filter.

[galaxy]

@Jangid, please read the original request and it specifically asks for the proper display of a local zone in the top of the page and not in the status line.

[Pankaj Jangid]

@galaxy Oh! yes. Just noticed that. Correct.

[kevr]

You're the best. AroOoOOund. And you're never gonna let us down!