date

First, print today's date:
$ date
Sun Jun 17 12:17:24 CDT 2007

Now display Yesterday's date:
$ date --date="1 days ago"
OR try:
$ date --date="yesterday"
Sat Jun 16 12:17:20 CDT 2007

Now display Tomorrow's date:
$ date --date="-1 days ago"
Or better try:
$ date --date="next day"
Sat Jun 16 12:17:20 CDT 2007

Getting date in the future

To get tomorrow and day after tomorrow (tomorrow+N) use day word to get date in the future.

Getting date in the past

To get yesterday and earlier day in the past use string day ago:

Moving by whole years or months

You can add year and months keywords to get more accurate date:
$ date --date='2 year ago' # past
$ date --date='3 years' # go into future
$ date --date='2 days' # future
$ date --date='1 month ago' # past
$ date --date='2 months' # future

Moving date using more precise units

• You can use fortnight for 14 day
• Week for 7 days
• hour for 60 minutes
• minute for 60 seconds
• second for one second
• You can also use this / now / today keywords to stress the meaning

To print the date of this Friday:
$ date --date='this Friday'
To print the date of the day six months and 15 day
$ date --date='6 months 15 day'
To print the date of the day two months and 5 days ago:
$ date --date='2 months 5 day ago'

You can also use relative format to setup date and time. For example to set the system clock forward by 30 minutes, enter:
# date --set='+30 minutes'

To display date in :
$ date --date='1970-01-01 00:00:01 UTC +5 hours' +%s