Linux date-d parameter usage

Lately I've racked my brains to write a shell that adjusts time, and it turns out that someday
#info data
It was ecstatic to see the flexible use of the data-d parameter. Good things to keep, tidy up:

* To print the date of the day before yesterday:

Date--date= ' 2 days ago '

* To print the date of the day three months and one day hence:

Date--date= ' 3 months 1 day '

* To print the day's of Christmas in the current year:

Date--date= ' Dec ' +%j

* To print the current full month name and the day of the month:

Date ' +%b%d '

Want because for the first nine days
Of the month, the '%d ' expands to a zero-padded two-digit field,
For example ' date-d 1may ' +%b%d ' would print ' May 01 '.

* To print a date without the leading zero for one-digit days of the
month, you can use the (GNU extension) '-' flag to suppress the
Padding altogether:

Date-d 1may ' +%b%-d

* To print the current date and time of the format required by many
Non-gnu versions of ' Date ' when setting the system clock:

Date +%m%d%h%m%y.%s

* To set the system clock forward by minutes:

Date--set= ' +2 minutes '

* To-print the date in RFC 2822 format with use ' Date--rfc-2822 '. Here
Is some example output:

Fri, Sep 2005 13:51:39-0700

* To convert a date string to the number of seconds since the epoch
(Which is 1970-01-01 00:00:00 UTC), use the '--date ' option with
The '%s ' format. That can is useful in sorting and/or graphing
and/or comparing data by date. The following command outputs the
Number of the seconds since the epoch for the time and the Minutes
After the epoch:

Date--date= ' 1970-01-01 00:02:00 +0000 ' +%s

Date--date= ' 1970-01-01 00:02:00 +0000 ' +%s
120

If You don't specify time zone information in the date string,
' Date ' uses your computer ' s idea of the time zone when
Interpreting the string. For example, if your computer ' s time
Zone is that's Cambridge, Massachusetts, which was and then 5 hours
(i.e., 18,000 seconds) behind UTC:

# local time zone used
Date--date= ' 1970-01-01 00:02:00 ' +%s
18120

* If you ' re sorting or graphing dated data, your raw date values may
Be represented as seconds since the epoch. But few people can
Look at the date ' 946684800 ' and casually note ' Oh, that ' s the
First second of the year in Greenwich, England. "

Date--date= ' 2000-01-01 UTC ' +%s
946684800

An alternative are to use the '--UTC ' ('-u ') option. Then, May
Omit ' UTC ' from the date string. Although this produces the same
Result for '%s ' and many other format sequences, with a time zone
Offset different from zero, it would give a different result for
Zone-dependent formats like '%z '.

Date-u--date=2000-01-01 +%s
946684800

To convert such an unwieldy number of seconds back to a more
Readable form, use a command like this:

# local time zone used
Date-d ' 1970-01-01 UTC 946684800 seconds ' + "%y-%m-%d%T%z"
1999-12-31 19:00:00-0500

Often It is better to output utc-relative date and time:

Date-u-d ' 1970-01-01 946684800 seconds ' + "%y-%m-%d%T%z"
2000-01-01 00:00:00 +0000

Linux date-d parameter usage