How can calculate date difference in linux?

How can calculate date difference in linux?

1. Provide valid time string in A and B.
2. Use date -d to handle time strings.
3. Use date %s to convert time strings to seconds since 1970 (unix epoche)
4. Use bash parameter expansion to subtract seconds.
5. divide by seconds per day (86400=60*60*24) to get difference as days.
6. ! DST is not taken into account ! See this answer at unix.

How do you subtract dates in shell?

@x_mtd Yes, you need to set the variable date_diff . Set it to the number of days that you want to subtract. Very slight improvement to the command – date –date=”${dataset_date} -${date_diff} day” +%Y-%m-%d.

How can I get tomorrow date in linux?

If you don’t have GNU date, you can use the built-in date command with the -v option. returns tomorrow’s date. returns tomorrow’s date in the format YYYY-MM-DD.

What is the command to show the date in Unix?

The syntax is:

1. date date “+format”
2. date.
3. date 0530.30.
4. date 10250045.
5. date –set=”20091015 04:30″
6. date ‘+DATE: %m/%d/%y%nTIME:%H:%M:%S’
7. date “+%m/%d/%y” date “+%Y%m%d” date +’%-4.4h %2.1d %H:%M’

How do I subtract two timestamps in Linux?

If you want to process the date using simple command line tools, you need to convert the timestamps into some easy-to-deal-with format, like epoch-based. Then you can subtract to get a number of milliseconds representing the diff.

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

5 Answers. There’s a solution that almost works: use the %s date format of GNU date, which prints the number of seconds since 1970-01-01 00:00. These can be subtracted to find the time difference between two dates. Because of daylight savings time, there are only 23 hours between those times.

How do I display yesterday’s date in Linux?

1. Yesterday date YES_DAT=$(date –date=’ 1 days ago’ ‘+%Y%d%m’)
2. Day before yesterdays date DAY_YES_DAT=$(date –date=’ 2 days ago’ ‘+%Y%d%m’)

How do you display AM or PM in Unix?

Options Related to Formatting

1. %p: Prints the AM or PM indicator in uppercase.
2. %P: Prints the am or pm indicator in lowercase. Note the quirk with these two options. A lowercase p gives uppercase output, an uppercase P gives lowercase output.
3. %t: Prints a tab.
4. %n: Prints a new line.

How to add or subtract dates in Linux?

Going into the future with date command is as easy as going into the past. All what needs to be done is to add “-” ( minus ) sign in front of every date string. For example you can ask date command to add 12 hours to a current date and time: On some Unix systems the date syntax described above may not be available.

What can you do with the date command in Linux?

The date command on Linux can be used to see the current date and time, but we can also use addition and subtraction arithmetic with the command to extend its functionality. For example, instead of seeing the current date, we can see the date and time from five days ago, five years in the future, etc. The possibilities here are endless.

When to use subtraction and addition in Linux?

One such example would be when you’re creating backups, you can use the date command to assign files a dated name, or even to delete older backups by using some substraction arithmetic. We’ll cover this specific example below so you can see it in action, but as you can imagine, there are many more cases where it would be handy.

How to subtract number of days from date in Bash?

I want to subtract “number of days” from a date in bash. I am trying something like this .. You are specifying the date incorrectly. Instead, say: If you need to store it in a variable, use $ (…):