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

If your epoch time is in milliseconds instead of seconds, either put a dot before last three digits (as hinted in comments by user79743), or remove the last three digits before passing it to date -d:

Entered directly, this gives incorrect result :

$ date -d @1455086371603 Tue Nov 7 02:46:43 PST 48079 #Incorrect 

Put a dot before last three digits:

$ date -d @1455086371.603 Tue Feb 9 22:39:32 PST 2016 #Correct 

Or, remove the last three digits:

$ date -d @1455086371 Tue Feb 9 22:39:31 PST 2016 #Correct after removing the last three digits. You may remove and round off the last digit too. 

date -d @1190000000 Replace 1190000000 with your epoch

With bash-4.2 or above:

$ printf '%(%FT%T%z)T\n' 1234567890 2009-02-13T23:31:30+0000 

(where %FT%T%z is the strftime()-type format, here using standard unambiguous format which includes the UTC offset (%z))

That syntax is inspired from ksh93.

In ksh93 however, the argument is taken as a date expression where various and hardly documented formats are supported.

For a Unix epoch time, the syntax in ksh93 is:

printf '%(%FT%T%z)T\n' '#1234567890' 

ksh93 however seems to use its own algorithm for the timezone and can get it wrong. For instance, in mainland Britain, it was summer time all year in 1970, but:

$ TZ=Europe/London bash -c 'printf "%(%c)T\n" 0' Thu 01 Jan 1970 01:00:00 BST $ TZ=Europe/London ksh93 -c 'printf "%(%c)T\n" "#0"' Thu Jan 1 00:00:00 1970 

ksh93 (and zsh's strftime builtin) support subsecond, not bash yet:

$ ksh -c 'printf "%(%FT%T.%6N%z)T\n" 1234567890.123456789' 2009-02-13T23:31:30.123456-0000 $ zsh -c 'zmodload zsh/datetime; strftime %FT%T.%6.%z 1234567890 123456780' 2009-02-13T23:31:30.123457+0000 

Custom format with GNU date:

date -d @1234567890 +'%Y-%m-%d %H:%M:%S' 

Or with GNU awk:

awk 'BEGIN { print strftime("%Y-%m-%d %H:%M:%S", 1234567890); }' 

Linked SO question: https://stackoverflow.com/questions/3249827/convert-from-unixtime-at-command-line

$ echo 1190000000 | perl -pe 's/(\d+)/localtime($1)/e' Sun Sep 16 20:33:20 2007 

This can come in handy for those applications which use epoch time in the logfiles:

$ tail -f /var/log/nagios/nagios.log | perl -pe 's/(\d+)/localtime($1)/e' [Thu May 13 10:15:46 2010] EXTERNAL COMMAND: PROCESS_SERVICE_CHECK_RESULT;HOSTA;check_raid;0;check_raid.pl: OK (Unit 0 on Controller 0 is OK) 

The two I frequently use are:

$ perl -leprint\ scalar\ localtime\ 1234567890 Sat Feb 14 00:31:30 2009 

and

$ tclsh % clock format 1234567890 Sa Feb 14 00:31:30 CET 2009 

With zsh you could use the strftime builtin:

strftime format epochtime Output the date denoted by epochtime in the format specified.

e.g.

zmodload zsh/datetime strftime '%A, %d %b %Y' 1234567890 

Friday, 13 Feb 2009

There's also dateconv from dateutils:

dateconv -i '%s' -f '%A, %d %b %Y' 1234567890 

Friday, 13 Feb 2009

keep in mind dateutils tools default to UTC (add -z your/timezone if needed).

In PowerShell:

(([System.DateTimeOffset]::FromUnixTimeMilliSeconds($unixtime)).DateTime).ToString("s") 

If UTC is your preference (for the sample epoch timestamp 1666666666),

$ # long options; Linux $ date --date=@1666666666 --utc Tue 14 Nov 22:13:20 UTC 2023 $ # short options; Linux $ date -d @1666666666 -u Tue 14 Nov 22:13:20 UTC 2023 

You could also use a little C program for printing the datetime in the format that can be directly parsed by shell

#include <stdio.h> #include <stdlib.h> #include <string.h> #include <time.h> int main(int argc, char * argv[]) { if (argc==1) { return 1; } struct tm input_tm; char * formatStr = "YEAR=%Y\nMON=%m\nDAY=%d\nHOUR=%H\nMIN=%M\nSEC=%S"; size_t formatSize = strlen(formatStr) + 2; char * output = (char *)malloc(sizeof(char)*formatSize); strptime(argv[1],"%s",&input_tm); strftime(output, formatSize, formatStr, &input_tm); printf("%s\n",output); free(output); return 0; } 

usage:

#compile clang -o epoch2datetime main.c #invoke eval `./epoch2datetime 1450196411` echo $YEAR $MON $DAY $HOUR $MIN $SEC #output #2015 12 16 00 20 11 

Wouldn't be a real solution without a little node.js:

epoch2date(){ node -p "new Date($1)" } 

add that to ~/.bash_aliases and make sure its sourced in ~/.bashrc with . ~/.bash_aliases

if [ -f ~/.bash_aliases ]; then . ~/.bash_aliases fi 

To get node on your system goto http://nvm.sh and run the curl command. It'll install node version manager (nvm) which allows you to switch versions of node.

Just type nvm ls-remote and pick a version to nvm install <version>.