How do you find the difference between two dates in Shell?

In a shell environment/script you can get it with date ‘+\%s’ At the time of writing, the current time is 1321358027 . To compare with 2011-11-04 (my birthday), date ‘+\%s’ -d 2011-11-04 , yielding 1320361200 . Subtract: expr 1321358027 – 1320361200 gives 996827 seconds, which is expr 996827 / 86400 = 11 days ago.

How do I subtract the current date in Unix?

4 Answers. The easiest way is to convert the date to a unix time_t value (i.e. seconds since the beginning of the epoch, or ‘1-1-1970 00:00:00’), and then substract 30 days * 86400 seconds per day from that number. e.g. the following example uses set -x so that you can see the value of the D variable as it changes.

Which date function is used to find the difference between two dates?

DATEDIF function
The DATEDIF function returns the difference between two full component standard dates in units of a specified component. A component is one of the following: Year. Using the year unit with DATEDIF yields the inverse of DATEADD.

How do you subtract a Unix shell script?

The following arithmetic operators are supported by Bourne Shell….Unix / Linux – Shell Arithmetic Operators Example.

How does shell script calculate time difference?

Seconds

1. Bash variable SECONDS (if SECONDS is unset it loses its special property).
2. Bash printf option \%(datefmt)T : a=”$(TZ=UTC0 printf ‘\%(\%s)T\n’ ‘-1’)” ### `-1` is the current time sleep 1 ### Process to execute elapsedseconds=$(( $(TZ=UTC0 printf ‘\%(\%s)T\n’ ‘-1’) – a ))

How do I get the 7 day back date in Unix?

1. pday=7 CURRENT= date +”\%F \%T” –date “$pday days ago” echo $CURRENT how abt this. – jcrshankar.
2. That’s fine. The shell handles replacing $pday with 7, so date gets the same argument to –date either way.
3. Likewise, GNU date is unlikely to be installed on a Unix system (likely only Linux and constructs such as Cygwin).

How do I calculate time difference between two dates in Excel?

Another simple technique to calculate the duration between two times in Excel is using the TEXT function:

1. Calculate hours between two times: =TEXT(B2-A2, “h”)
2. Return hours and minutes between 2 times: =TEXT(B2-A2, “h:mm”)
3. Return hours, minutes and seconds between 2 times: =TEXT(B2-A2, “h:mm:ss”)

How do you subtract two dates?

Here’s how:

1. Type a start time and end time. In this example, the start time is in cell D80 and the end time is in E80.
2. Set the h:mm AM/PM format. Select both dates and press CTRL + 1 (or.
3. Subtract the two times. In another cell, subtract the start time cell from the end time cell.
4. Set the h:mm format. Press CTRL + 1 (or.

How do I find the difference between two dates in SQL query?

To find the difference between dates, use the DATEDIFF(datepart, startdate, enddate) function. The datepart argument defines the part of the date/datetime in which you’d like to express the difference. Its value can be year , quarter , month , day , minute , etc.

How to calculate the difference between two dates of the same year?

Another way to calculate the difference between two dates of the same calendar year you could use this: date_difference.sh 1 #!/bin/bash 2 DATEfirstnum=`date -d “2014/5/14” +”\%j”` 3 DATElastnum=`date -d “12/31/14” +”\%j”` 4 DAYSdif=$ (($DATElastnum – $DATEfirstnum)) 5 echo “$DAYSdif” Line 1 declares to the shell which interpreter to use.

How to get the time difference between two times?

You can use date (assuming the GNU implementation) with command substitution, and to get the difference between the times use arithmetic expansion: The result is in seconds. Note in opposite to the date command, dateutils ignores locale settings by default using GMT.

How to get the difference between date and DATEDIFF?

You can use date (assuming the GNU implementation) with command substitution, and to get the difference between the times use arithmetic expansion: The result is in seconds. datediff is from the dateutuils package. Note in opposite to the date command, dateutils ignores locale settings by default using GMT.

How to get seconds since the epoch in GNU date?

With GNU date, the -d argument can be prepended with @ to indicate “Seconds since the Epoch” format. This came up when using date -d “$death_date – $y years – $m months – $d days” to get a birth date (for genealogy). That command is WRONG.