the "date" tag is used to classify questions about date/calendar/time manipulation, visualisation, conversion... on Unix-like systems.

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77
votes
3answers
41k views

Day of week {0-7} in crontab has 8 options, but we have only 7 days in a week

Day-of-week: Allowed range 0 – 7. Sunday is either 0 or 7. I found this after Googling, my question is why should both values (0,7) correspond to Sunday?
69
votes
11answers
84k views

How do I convert an epoch timestamp to a human readable format on the cli?

How do I convert an epoch timestamp to a human readable format on the cli? I think there's a way to do it with date but the syntax eludes me (other ways welcome).
46
votes
6answers
44k views

How can I have `date` output the time from a different timezone?

I have a server running with the timezone set to UTC. It seemed like that was generally a good practice (please correct me if I'm wrong). Anyhow, one of the servers I connect to, in order to scp ...
41
votes
4answers
52k views

last time file opened

Is it possible to get the time when file was opened last time and sort all files in a directory by those times?
38
votes
9answers
83k views

Quickly calculate date differences

I often want to make some quick date calculations, such as: What is the difference between these two dates? What is the date n weeks after this other date? I usually open a calendar and count the ...
38
votes
3answers
186k views

Timezone setting in Linux [closed]

I'm setting the timezone to GMT+6 on my Linux machine by copying the zoneinfo file to /etc/localtime, but the date command is still showing the time as UTCtime-6. Can any one explain to me this ...
30
votes
3answers
89k views

linux + add X days to date and get new virtual date

I have Linux ( RH 5.3) machine I need to add/calculate 10 days plus date so then I will get new date (expiration date)) for example # date Sun Sep 11 07:59:16 IST 2012 So I need to get ...
29
votes
10answers
4k views

Year 2038 problem [closed]

What is the likelihood of the Year 2038 issue being very problematic?
27
votes
4answers
27k views

How to list files sorted by modification date recursively (no stat command available!)

How can I get the list of all files under current directory along with their modification date and sorted by that date? Now I know how to achieve that with find, stat and sort, but for some weird ...
26
votes
4answers
155k views

Linux: set date through command line

How to change the system date in Linux ? I want to change: Only Year Only Month Only Date Any combination of above three
19
votes
3answers
3k views

How does touch -t work internally?

How does touch -t command works exactly, internally (I tried to find its source code but couldn't)?
19
votes
6answers
64k views

How to append date to backup file

I need to make a backup of a file, and I would like to have a timestamp as part of the name to make it easier to differentiate. How would you inject the current date into a copy command? [root@...
18
votes
8answers
13k views

Tool in UNIX to subtract dates

Is there any tool in Solaris UNIX (so no GNU tool available) to subtract dates? I know that in Linux we have gawk that can subtract one date from another. But in Solaris the maximum we have is nawk (...
17
votes
2answers
29k views

show the year while listing files in the current directory

I am working on a red hat server I want to list the files in a way where the year when each was file created would appear in the Date how is that possible ?
17
votes
4answers
10k views

How can I avoid “Run fsck manually” messages while allowing experimenting with system time changes?

I'm working with a system where we want to allow users to play around with the date and time if they want, and where reboots may happen arbitrarily. This is fine, except for one thing: if there's a ...
17
votes
1answer
2k views

How to trick a particular command into thinking it is a different date?

How can I execute a command making it believe that is on a different date than system one? For instance, if I have this script: #!/usr/bin/env bash date +"%B %d, %Y" It prints the actual date: ...
15
votes
5answers
64k views

Appending a current date from a variable to a filename

I'm trying to append the current date to the end of a file name like this: TheFile.log.2012-02-11 Here is what I have so far: set today = 'date +%Y' mkdir -p The_Logs & find . -name The_Logs -...
14
votes
3answers
2k views

Date validation in shell

I want to validate the below date format in shell script 2015-Jul-13 I'm using date -d "2015-Jul-13" +"%Y-%b-%d" but its giving error as date: invalid date '2015-Jul-13'
14
votes
4answers
5k views

Why does TZ=UTC-8 produce dates that are UTC+8?

The current time in Los Angeles is 18:05. But when I run TZ=UTC-8 date --iso=ns, I get: 2013-12-07T10:05:37,788173835+0800 The date utility tells me that the time is 10:05, and even says that it's ...
14
votes
4answers
7k views

how to suppress bash octal number interpretation? (to be interpreted as decimal)

I have this: date +"%H hours and %M minutes" I use festival to say it up.. but it says like: "zero nine hours".. I want it to say "nine hours"! but date always give me 09... so I wonder if bash ...
13
votes
9answers
16k views

How to chain the commands 'date -d @xxxxxx' and 'find ./'?

I have directories whose names are timestamps, given in milliseconds since 1970-01-01: 1439715011728 1439793321429 1439879712214 . . And I need an output like: 1442039711 Sat Sep 12 08:35:11 ...
13
votes
1answer
8k views

Removing leading zeros from DATE

I made an alias of the date command to display date in the following format: 2013.06.14.12.10.02 using this command: alias date = date +"%Y.%m.%d.%H.%M.%S" Everything works great, except I ...
13
votes
3answers
8k views

What is the recommended way to synchronize time using NTP?

This question has come up a number of times in a localized way, this question is meant to provide the preferred/best method for synchronizing a system's clock using NTP. The solution should handle ...
12
votes
3answers
2k views

How do I get the current time in a different time zone without changing system time? [duplicate]

I am trying to use 'date' to get the time in a different time zone, and failing. All the methods I've found on google involve changing the time zone on the system, but that is not what I want. Is ...
12
votes
6answers
12k views

date: get current 15 minute interval

Is there any way I can get the current 15 minute interval using the date command or similar ? e.g. something like date %Y.%m.%d %H:%M will give me 2011.02.22 10:19 , I need something that yields ...
12
votes
2answers
4k views

date command --iso-8601 option

This answer and comments mention --rfc-3339 and a "hidden" --iso-8601 option that I have used for a long time and now seems to be undocumented. When did that option documentation get removed from the ...
11
votes
2answers
1k views

date - years prior to 1901 are treated as invalid

I have date (GNU coreutils) 7.1 installed on my system. If I try to check dates prior to 14-Dec-1901, I get an "invalid date" error. For example, $ date -d 1901-12-13 date: invalid date `1901-12-...
10
votes
7answers
19k views

How do I set time and date from the Internet?

How do I retrieve the date from the Internet and set my computer's clock, from the command line?
10
votes
3answers
963 views

What's a smart way to count the number of days since X?

I started working at my current position since November 17th 2014. I would like to know how many days have run up to now. Any ideas on how to use Linux to come up with a simple and nice solution ?
10
votes
5answers
76k views

Display time stamp in dd/mm/yyyy_hh:mm:ss:ms in Unix or Linux

I need help to display date and time in desired format in Unix/ Linux. My desired format is: dd/mm/yyyy hh:mm:ss:ms in Unix or Linux. I got close using the following command: echo $(date +%x_%r) ...
10
votes
4answers
29k views

Getting all files that have been modified on a specific date

Is it possible to find all php files within a certain directory that have been modified on a certain date I'm using find /var/www/html/dir/ -mtime -28 | grep '\.php' to get files modified within ...
10
votes
3answers
3k views

How to use the date command to find out what date “monday week 40” will be?

How can I use the date command to convert something like "monday week 40" into a ISO date? I am playing with something like this: date --date='monday week 40' +'%Y-%m-%d' And the date I'm ...
10
votes
2answers
770 views

What is a distro-agnostic way determine the OS install date?

I am on a CrunchBang machine and trying to write a script that needs to have the OS install date as a reference. I searched and found this command: ls -lct /etc | tail -1 | awk '{print $6, $7, $8}' ...
9
votes
4answers
12k views

Renaming a bunch of files with date modified timestamp at the end of the filename?

So, say, I have a directory with a bunch of files like g.txt, where g.txt was last modified on, say, June 20, 2012. How would I batch-rename all of the files (like g.txt) with the last modified date ...
9
votes
5answers
10k views

How to parse ISO8601 dates with linux date command

I'm trying to use the date command to generate a file timestamp that the date command itself can interpret. However, the date command does not seem to like its own output, and I am not sure how to ...
9
votes
2answers
2k views

How can I delete all files in a folder that haven't been accessed in a certain amount of time?

I'd like to run a nightly cron job that deletes all the files in a folder that haven't been accessed in a week or more. What is the most efficient way to do this in bash?
9
votes
2answers
3k views

Using environment variables in Tmux status bar shell commands

I am attempting to create a tmux status bar which shows three timezones: US Eastern Time :: UTC :: Central European Time. Using the TZ environment variable makes the date command show the time in a ...
9
votes
4answers
1k views

Forcing an 'added' alias to every command

Is it possible to forcibly add a timing alias (for lack of a better way to phrase it) to every command in bash? For example, I would like to have a specific user who whenever a command is run, it is ...
9
votes
1answer
285 views

Why are these 2 date commands giving different results?

$ date -d "Apr 1 2016 - 1 month" +%B gives me "March", which is great - the month that comes before April is March. If I do this however: $ date -d "$(date -d "Apr 1 2016") - 1 month" +%B it ...
9
votes
2answers
7k views

How do you specify a format for the input to date?

Given a date and time in a format that is not recognized by date, how can I get date to recognize the date and time? For example: $ date -d "09SEP2012:23:58:46" date: invalid date `09SEP2012:23:58:...
9
votes
2answers
4k views

Is there a way to adjust the formatting of the date/time in the GNOME 3 login screen and desktop?

I'm specifically looking to change the formatting in two places: On the desktop, the date/time reads "Sat 21:05". I would like it to read "23-Jul-11 21:05" or "23 Jul 11 21:05". In other words, I ...
8
votes
3answers
26k views

List of Recently Modified Files

How can I Get a list of all files modified , say 3 months ago. I checked this question but I was not able to apply it to my scenario. I am trying this now , it seems to be working , but I know there ...
8
votes
3answers
1k views

sort at jobs chronologically

Possibly a simple solution I misplaced. How can I get the output of atq sorted chronologically, so I can easily see who's due to run next? The man page for sort doesn't have anything built-in to ...
8
votes
2answers
10k views

How to find difference between two timestamps up to milliseconds?

I am new to shell scripting. The heart of my script is to find the difference between two timestamps up to milliseconds. With me I have a file with content of timestamps only as 2012-09-13 15:00:29,...
7
votes
4answers
4k views

What is a standard command for printing a date in RFC-3339 format?

The date command doesn't offer such thing, which is kind of sad since RFC-3339 is the modern, widespread, sane format used everywhere (except in email which is neither modern nor sane). My timezone ...
7
votes
4answers
28k views

Appending timestamp stamp along with log file lines

I have a log file and I need to append timestamps to each line as they get added. So I'm looking for script that appends timestamps to each entry in log lines and which could run as a cron job. Could ...
7
votes
2answers
17k views

Good method to compare time?

I need to check for the current time and abort the script if it is not proper time of day I am supposed to run it. Also, if anyone else runs it, it should abort. For example: I need my script to only ...
7
votes
4answers
1k views

Date computations without GNU tools

I have to perform some date calculations and conversion in a shell script. For example computing the difference in day between a date formatted as Nov 28 20:27:19 2012 GMT and today. There are ...
7
votes
1answer
271 views

Change a locale definition (as opposed to a locale setting)

Preliminary remark: This question is not about setting a locale by changing LC_ALL, LC_TIME, LANG, etc., it's rather about changing a locale definition, e.g. in /usr/share/i18n/locales/de_DE, or ...
7
votes
1answer
680 views

Why does the syslog timestamp not include a year?

I am planning to store some of my log messages for more than a year, but the syslog timestamp description from RFC3164 does not include a year in the timestamp portion of a log entry. An example ...