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Get the date from yesterday in bash on Linux, DST-aware


I have a Linux shell script that utilizes this call to retrieve the date from yesterday in YYYY-MM-DD format:

date -d "1 day ago" '+%Y-%m-%d'

It works most of the time, but it returned “2013-03-09” instead of “2013-03-10” when the script was run yesterday morning at 0:35 CDT.

It’s very likely that Daylight Saving Time (which began yesterday) is to blame. I’m presuming “1 day ago” is calculated by subtracting 24 hours, because 24 hours before 2013-03-11 0:35 CDT was 2013-03-09 23:35 CST, resulting in “2013-03-09.”

So, with bash on Linux, what’s a nice DST-safe approach to retrieve yesterday’s date?

Asked by Ike Walker

Solution #1

I believe this will work regardless of how often or when you run it…

date -d "yesterday 13:00" '+%Y-%m-%d'

Answered by tink

Solution #2

Date operates a little differently on Mac OSX:

For yesterday

date -v-1d +%F

For Last week

date -v-1w +%F

Answered by Aries

Solution #3

This should work as well, but it may be too much:

date -d @$(( $(date +"%s") - 86400)) +"%Y-%m-%d"

Answered by perreal

Solution #4

If you know the script will execute in the early hours of the day, you can just do

  date -d "12 hours ago" '+%Y-%m-%d'

BTW, if the script runs every day at 00:35 (through crontab? ), you should consider what would happen if the DST changes during that hour; the script may not execute, or may run twice. However, modern cron implementations are pretty sophisticated in this area.

Answered by leonbloy

Solution #5

date -d "yesterday" '+%Y-%m-%d'

To put this to use later:

date=$(date -d "yesterday" '+%Y-%m-%d')

Answered by suresh Palemoni

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