Date Shift Script - Revision history

Root: /* Example Usage */

2009-10-02T19:10:43Z

Example Usage

← Older revision		Revision as of 19:10, 2 October 2009
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	==Example Usage==		==Example Usage==
	# Add five days to 2006-03-01: <nowiki>		* Add five days to 2006-03-01: <nowiki>
	</nowiki>		</nowiki>
	<pre><nowiki>		<pre><nowiki>
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	20060306		20060306
	</nowiki></pre>		</nowiki></pre>
	# Add 12 hours to 20060304 06:00: <nowiki>		* Add 12 hours to 20060304 06:00: <nowiki>
	</nowiki>		</nowiki>
	<pre><nowiki>		<pre><nowiki>
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	20060304 18:00		20060304 18:00
	</nowiki></pre>		</nowiki></pre>
	# Subtract five days and six hours from 20060308: <nowiki>		* Subtract five days and six hours from 20060308: <nowiki>
	</nowiki>		</nowiki>
	<pre><nowiki>		<pre><nowiki>

Root: Text replace - '

' to '
'

2009-10-02T19:07:38Z

Text replace - '<pre>' to ' <pre>'

← Older revision		Revision as of 19:07, 2 October 2009
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	==dateshift==		==dateshift==
	I use the following simple UNIX script to add or substract number of days from a given date and print the result. <nowiki>		I use the following simple UNIX script to add or substract number of days from a given date and print the result. <nowiki>
	</nowiki><pre><nowiki>		</nowiki>
			<pre><nowiki>
	#!/bin/bash		#!/bin/bash
	fmt="+%Y%m%d"		fmt="+%Y%m%d"
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	==Example Usage==		==Example Usage==
	# Add five days to 2006-03-01: <nowiki>		# Add five days to 2006-03-01: <nowiki>
	</nowiki><pre><nowiki>		</nowiki>
			<pre><nowiki>
	$ dateshift 5 20060301		$ dateshift 5 20060301
	20060306		20060306
	</nowiki></pre>		</nowiki></pre>
	# Add 12 hours to 20060304 06:00: <nowiki>		# Add 12 hours to 20060304 06:00: <nowiki>
	</nowiki><pre><nowiki>		</nowiki>
			<pre><nowiki>
	$ dateshift .5 "20060304 06:00" "+%Y%m%d %H:%M"		$ dateshift .5 "20060304 06:00" "+%Y%m%d %H:%M"
	20060304 18:00		20060304 18:00
	</nowiki></pre>		</nowiki></pre>
	# Subtract five days and six hours from 20060308: <nowiki>		# Subtract five days and six hours from 20060308: <nowiki>
	</nowiki><pre><nowiki>		</nowiki>
			<pre><nowiki>
	$ dateshift -5.25 20060308 "+%Y%m%d %H:%M"		$ dateshift -5.25 20060308 "+%Y%m%d %H:%M"
	20060302 18:00		20060302 18:00

Root at 01:55, 2 May 2006

2006-05-02T01:55:54Z

← Older revision		Revision as of 01:55, 2 May 2006
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	Just save it somewhere in the Cygwin path (e.g. <tt>/usr/local/bin</tt> is a good place) as dateshift and make it executable (<tt>[[UNIX filesystem permissoins tutorial\|chmod u+x datescript]]</tt>)		Just save it somewhere in the Cygwin path (e.g. <tt>/usr/local/bin</tt> is a good place) as dateshift and make it executable (<tt>[[UNIX filesystem permissoins tutorial\|chmod u+x datescript]]</tt>)

	~~[[Category:Unix]][[Category:Computing]]~~

	==Example Usage==		==Example Usage==
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	20060302 18:00		20060302 18:00
	</nowiki></pre>		</nowiki></pre>

			[[Category:Unix]][[Category:Computing]]

Root: /* dateshift */

2006-05-02T01:55:27Z

dateshift

← Older revision		Revision as of 01:55, 2 May 2006
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	</nowiki></pre>		</nowiki></pre>
	Just save it somewhere in the Cygwin path (e.g. <tt>/usr/local/bin</tt> is a good place) as dateshift and make it executable (<tt>[[UNIX filesystem permissoins tutorial\|chmod u+x datescript]]</tt>)		Just save it somewhere in the Cygwin path (e.g. <tt>/usr/local/bin</tt> is a good place) as dateshift and make it executable (<tt>[[UNIX filesystem permissoins tutorial\|chmod u+x datescript]]</tt>)

			[[Category:Unix]][[Category:Computing]]

	==Example Usage==		==Example Usage==

Root: /* dateshift */

2006-05-02T01:54:31Z

dateshift

← Older revision		Revision as of 01:54, 2 May 2006
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	date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"		date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"
	</nowiki></pre>		</nowiki></pre>
	Just save it somewhere in the Cygwin path (e.g. /usr/local/bin is a good place) as dateshift and make it executable ([[UNIX filesystem permissoins tutorial\|chmod u+x datescript]])		Just save it somewhere in the Cygwin path (e.g. <tt>/usr/local/bin</tt> is a good place) as dateshift and make it executable (<tt>[[UNIX filesystem permissoins tutorial\|chmod u+x datescript]]</tt>)

	==Example Usage==		==Example Usage==
	# Add five days to 2006-03-01: <nowiki>		# Add five days to 2006-03-01: <nowiki>

Root at 01:54, 2 May 2006

2006-05-02T01:54:01Z

← Older revision		Revision as of 01:54, 2 May 2006
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	date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"		date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"
	</nowiki></pre>		</nowiki></pre>
			Just save it somewhere in the Cygwin path (e.g. /usr/local/bin is a good place) as dateshift and make it executable ([[UNIX filesystem permissoins tutorial\|chmod u+x datescript]])
	==Example Usage==		==Example Usage==
	# Add five days to 2006-03-01: <nowiki>		# Add five days to 2006-03-01: <nowiki>

Root at 01:50, 2 May 2006

2006-05-02T01:50:58Z

← Older revision		Revision as of 01:50, 2 May 2006
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	Let's face it: Solar system is a mess as far as time units are concerned! There are some 365.2425 days and is reducing with time!! We have largely simplified the system by adopting various convensions in the standard calendar, still there are occational jumps of dates here are there. This causes numerous problems in writing programs that operate on dates. Perhaps the best bet is to use a standard date function provided by an operating system as the basis, for these systems have been widely researched and tested.		Let's face it: Solar system is a mess as far as time units are concerned! There are some 365.2425 days and is reducing with time!! We have largely simplified the system by adopting various convensions in the standard calendar, still there are occational jumps of dates here are there. This causes numerous problems in writing programs that operate on dates. Perhaps the best bet is to use a standard date function provided by an operating system as the basis, for these systems have been widely researched and tested.
			==dateshift==
	I ~~have written~~ the following UNIX script to add or substract number of days from a given date and print the result. <nowiki>		I use the following simple UNIX script to add or substract number of days from a given date and print the result. <nowiki>
	</nowiki><pre><nowiki>		</nowiki><pre><nowiki>
	#!/bin/bash		#!/bin/bash

Root at 01:50, 2 May 2006

2006-05-02T01:50:04Z

← Older revision		Revision as of 01:50, 2 May 2006
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	fmt="+%Y%m%d"		fmt="+%Y%m%d"
	if [ $# -lt 1 ]; then		if [ $# -lt 1 ]; then
	~~echo "~~Usage: $0 ndates date [ADD/SUB]"		cat << EOF
	~~echo "~~default format is $fmt"		Usage: $0 ndates date [ADD/SUB] [fmt]
	~~echo "~~format should be YYYYMMDD or any other acceptable format for date command"		default format is $fmt
	~~echo "~~full precision down to seconds (if specified will be computed) but only up to date will be printed by default"		format should be YYYYMMDD or any other acceptable format for date command
	~~echo "~~default is to add"		full precision down to seconds (if specified will be computed) but only
	~~echo "~~if third argument is SUB, then substracted"		up to date will be printed by default
	~~echo "~~if a forth argument is present, it is treated as the format specifier for output. e.g. '+%Y%m%d%H%M%S' to get full precision"		default is to add
			if third argument is SUB, then substracted
			if a forth argument is present, it is treated as the format specifier
			for output. e.g. '+%Y%m%d%H%M%S' to get full precision
			(Assela Pathirana, 2006)
			EOF
	exit 1		exit 1
	fi		fi
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	thisdate=`date +'%s'`		thisdate=`date +'%s'`
	fi		fi
	if [ ! "$3" == 'SUB' ];then		if [ ! "$3" == 'SUB' ];then
			newdate=`echo $thisdate $dates\|awk '{printf "%20i", $1-$2243600}'`
			else
	newdate=`echo $thisdate $dates\|awk '{printf "%20i", $1+$2243600}'`		newdate=`echo $thisdate $dates\|awk '{printf "%20i", $1+$2243600}'`
	~~else~~
	~~newdate=`echo $thisdate $dates\|awk '{printf "%20i", $1-$2243600}'`~~
	fi		fi
	if [ $# -ge 4 ]; then		if [ $# -ge 4 ]; then
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	date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"		date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"
			</nowiki></pre>
			==Example Usage==
			# Add five days to 2006-03-01: <nowiki>
			</nowiki><pre><nowiki>
			$ dateshift 5 20060301
			20060306
			</nowiki></pre>
			# Add 12 hours to 20060304 06:00: <nowiki>
			</nowiki><pre><nowiki>
			$ dateshift .5 "20060304 06:00" "+%Y%m%d %H:%M"
			20060304 18:00
			</nowiki></pre>
			# Subtract five days and six hours from 20060308: <nowiki>
			</nowiki><pre><nowiki>
			$ dateshift -5.25 20060308 "+%Y%m%d %H:%M"
			20060302 18:00
	</nowiki></pre>		</nowiki></pre>

Root at 01:09, 2 May 2006

2006-05-02T01:09:51Z

New page

Let's face it: Solar system is a mess as far as time units are concerned! There are some 365.2425 days and is reducing with time!! We have largely simplified the system by adopting various convensions in the standard calendar, still there are occational jumps of dates here are there. This causes numerous problems in writing programs that operate on dates. Perhaps the best bet is to use a standard date function provided by an operating system as the basis, for these systems have been widely researched and tested.

I have written the following UNIX script to add or substract number of days from a given date and print the result. <nowiki>
</nowiki><pre><nowiki>
#!/bin/bash
fmt="+%Y%m%d"
if [ $# -lt 1 ]; then
echo "Usage: $0 ndates date [ADD/SUB]"
echo "default format is $fmt"
echo "format should be YYYYMMDD or any other acceptable format for date command"
echo "full precision down to seconds (if specified will be computed) but only up to date will be printed by default"
echo "default is to add"
echo "if third argument is SUB, then substracted"
echo "if a forth argument is present, it is treated as the format specifier for output. e.g. '+%Y%m%d%H%M%S' to get full precision"

exit 1
fi
dates=$1
if [ $# -ge 2 ]; then
thisdate=`date --date "$2" +'%s'`
else
date=''
thisdate=`date +'%s'`
fi
if [ ! "$3" == 'SUB' ];then
newdate=`echo $thisdate $dates|awk '{printf "%20i", $1+$2*24*3600}'`
else
newdate=`echo $thisdate $dates|awk '{printf "%20i", $1-$2*24*3600}'`
fi
if [ $# -ge 4 ]; then
fmt=$4
fi

date --date=" 1970-01-01 00:00:00 UTC $newdate seconds" "$fmt"

</nowiki></pre>

Date Shift Script - Revision history

Root: /* Example Usage */

Root: Text replace - '' to ' '

Root at 01:55, 2 May 2006

Root: /* dateshift */

Root: /* dateshift */

Root at 01:54, 2 May 2006

Root at 01:50, 2 May 2006

Root at 01:50, 2 May 2006

Root at 01:09, 2 May 2006

Root: Text replace - '
' to '
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