Dateutils
Dateutils are a bunch of tools that revolve around fiddling with dates and times on the command line with a strong focus on use cases that arise when dealing with large amounts of financial data.
Dateutils are hosted primarily on github:
- github page: https://github.com/hroptatyr/dateutils
- project homepage: http://www.fresse.org/dateutils/
- downloads: https://bitbucket.org/hroptatyr/dateutils/downloads
Below is a short list of examples that demonstrate what dateutils can do, for full specs refer to the info and man pages. For installation instructions refer to the INSTALL file.
Dateutils commands are prefixed with a date but otherwise resemble
known unix commands for reasons of intuition. The only exception being
strptime which is analogous to the libc function of the same name.
strptimeCommand line version of the C functiondateaddAdd durations to dates or timesdateconvConvert dates or times between calendarsdatediffCompute durations between dates or timesdategrepGrep dates or times in input streamsdateroundRound dates or times to "fuller" valuesdateseqGenerate sequences of dates or timesdatesortSort chronologically.datetestCompare dates or timesdatezoneConvert date/times to timezones in bulk
Examples
I love everything explained by example to get a first impression. So here it comes.
dateseq
A tool mimicking seq(1) but whose inputs are from the domain of dates rather than integers. Typically scripts use something like
$ for i in $(seq 0 9); do
date -d "2010-01-01 +${i} days" "+%F"
done
which now can be shortened to
$ dateseq 2010-01-01 2010-01-10
with the additional benefit that the end date can be given directly instead of being computed from the start date and an interval in days. Also, it provides date specific features that would be a PITA to implement using the above seq(1)/date(1) approach, like skipping certain weekdays:
$ dateseq 2010-01-01 2010-01-10 --skip sat,sun
=>
2010-01-01
2010-01-04
2010-01-05
2010-01-06
2010-01-07
2010-01-08
dateseq also works on times:
$ dateseq 12:00:00 5m 12:17:00
=>
12:00:00
12:05:00
12:10:00
12:15:00
and also date-times:
$ dateseq --compute-from-last 2012-01-02T12:00:00 5m 2012-01-02T12:17:00
=>
2012-01-02T12:02:00
2012-01-02T12:07:00
2012-01-02T12:12:00
2012-01-02T12:17:00
dateconv
A tool to convert dates between different calendric systems and/or time zones. While other such tools usually focus on converting Gregorian dates to, say, the Chinese calendar, dconv aims at supporting calendric systems which are essential in financial contexts.
To convert a (Gregorian) date into the so called ymcw representation:
$ dateconv 2012-03-04 -f "%Y-%m-%c-%w"
=>
2012-03-01-00
and vice versa:
$ dateconv 2012-03-01-Sun -i "%Y-%m-%c-%a" -f '%F'
=>
2012-03-04
where the ymcw representation means, the %c-th %w of the month in
a given year. This is useful if dates are specified like, the third
Thursday in May for instance.
dateconv can also be used to convert occurrences of dates, times or date-times in an input stream on the fly
$ dateconv -S -i '%b/%d %Y at %I:%M %P' <<EOF
Remember we meet on Mar/03 2012 at 02:30 pm
EOF
=>
Remember we meet on 2012-03-03T14:30:00
and most prominently to convert between time zones:
$ dateconv --from-zone "America/Chicago" --zone "Asia/Tokyo" 2012-01-04T09:33:00
=>
2012-01-05T00:33:00
$ dateconv --zone "America/Chicago" now -f "%d %b %Y %T"
=>
05 Apr 2012 11:11:57
datetest
A tool to perform date comparison in the shell, it's modelled after
test(1) but with proper command line options.
$ if datetest today --gt 2010-01-01; then
echo "yes"
fi
=>
yes
dateadd
A tool to perform date arithmetic (date maths) in the shell. Given a date and a list of durations this will compute new dates. Given a duration and a list of dates this will compute new dates.
$ dateadd 2010-02-02 +4d
=>
2010-02-06
$ dateadd 2010-02-02 +1w
=>
2010-02-09
$ dateadd -1d <<EOF
2001-01-05
2001-01-01
EOF
=>
2001-01-04
2000-12-31
Adding durations to times:
$ dateadd 12:05:00 +10m
=>
12:15:00
and even date-times:
$ dateadd 2012-03-12T12:05:00 -1d4h
=>
2012-03-11T08:05:00
If supported by the system's zoneinfo database leap-second adjusted
calculations are possible. Use the unit rs to denote "real" seconds:
$ dateadd '2012-06-30 23:59:30' +30rs
=>
2012-06-30T23:59:60
as opposed to:
$ dateadd '2012-06-30 23:59:30' +30s
=>
2012-07-01T00:00:00
datediff
A tool to calculate the difference between two (or more) dates. This is somewhat the converse of dadd. Outputs will be durations that, when added to the first date, give the second date.
Get the number of days between two dates:
$ datediff 2001-02-08 2001-03-02
=>
22
The duration format can be controlled through the -f switch:
$ datediff 2001-02-08 2001-03-09 -f "%m month and %d day"
=>
1 month and 1 day
datediff also accepts time stamps as input:
$ datediff 2012-03-01T12:17:00 2012-03-02T14:00:00
=>
92580s
The -f switch does the right thing:
$ datediff 2012-03-01T12:17:00 2012-03-02T14:00:00 -f '%dd %Ss'
=>
1d 6180s
compare to:
$ datediff 2012-03-01T12:17:00 2012-03-02T14:00:00 -f '%dd %Hh %Ss'
=>
1d 1h 2580s
If supported by the system's zoneinfo database leap-second adjusted
calculations can be made. Use the format specifier %rS to get the
elapsed time in "real" seconds:
datediff '2012-06-30 23:59:30' '2012-07-01 00:00:30' -f '%rS'
=>
61
dategrep
A tool to extract lines from an input stream that match certain criteria, showing either the line or the match:
$ dategrep '<2012-03-01' <<EOF
Feb 2012-02-28
Feb 2012-02-29 leap day
Mar 2012-03-01
Mar 2012-03-02
EOF
=>
Feb 2012-02-28
Feb 2012-02-29 leap day
dateround
A tool to "round" dates or time stamps to a recurring point in time, like the next/previous January or the next/previous Thursday.
Round (backwards) to the first of the current month:
$ dateround '2011-08-22' -1
=>
2011-08-01
Find the next Monday from the current date (today is 2016-01-08):
$ dateround today Mon
=>
2015-01-11
Go back to last September, then round to the end of the month:
$ dateround today -- -Sep +31d
=>
2015-09-30
Round a stream of dates strictly to the next month's first:
$ dateround -S -n 1 <<EOF
pay cable 2012-02-28
pay gas 2012-02-29
pay rent 2012-03-01
redeem loan 2012-03-02
EOF
=>
pay cable 2012-03-01
pay gas 2012-03-01
pay rent 2012-04-01
redeem loan 2012-04-01
Round a timeseries to the next minute (i.e. the seconds part is 00) and then to the next half-past time (and convert to ISO):
$ dateround -S 0s30m -i '%d/%m/%Y %T' -f '%F %T' <<EOF
06/03/2012 14:27:12 eventA
06/03/2012 14:29:59 eventA
06/03/2012 14:30:00 eventB
06/03/2012 14:30:01 eventB
EOF
=>
2012-03-06 14:30:00 eventA
2012-03-06 14:30:00 eventA
2012-03-06 14:30:00 eventB
2012-03-06 15:30:00 eventB
Alternatively, if you divide the day into half-hours you can round to one of those using the co-class notation:
$ dateround -S /30m -i '%d/%m/%Y %T' -f '%F %T' <<EOF
06/03/2012 14:27:12 eventA
06/03/2012 14:29:59 eventA
06/03/2012 14:30:00 eventB
06/03/2012 14:30:01 eventB
EOF
=>
2012-03-06 14:30:00 eventA
2012-03-06 14:30:00 eventA
2012-03-06 14:30:00 eventB
2012-03-06 15:00:00 eventB
This is largely identical to the previous example except, that a full hour (being an even multiple of half-hours) is a possible rounding target.
datesort
A tool to bring the lines of a file into chronological order.
At the moment the datesort tool depends on sort(1) with support
for fields, in particular -t to select a separator and -k to sort
by a particular field.
$ datesort <<EOF
2009-06-03 caev="DVCA" secu="VOD" exch="XLON" xdte="2009-06-03" nett/GBX="5.2"
2011-11-16 caev="DVCA" secu="VOD" exch="XLON" xdte="2011-11-16" nett/GBX="3.05"
2013-11-20 caev="DVCA" secu="VOD" exch="XLON" xdte="2013-11-20" nett/GBX="3.53"
2012-06-06 caev="DVCA" secu="VOD" exch="XLON" xdte="2012-06-06" nett/GBX="6.47"
2013-06-12 caev="DVCA" secu="VOD" exch="XLON" xdte="2013-06-12" nett/GBX="6.92"
2010-11-17 caev="DVCA" secu="VOD" exch="XLON" xdte="2010-11-17" nett/GBX="2.85"
EOF
=>
2009-06-03 caev="DVCA" secu="VOD" exch="XLON" xdte="2009-06-03" nett/GBX="5.2"
2010-11-17 caev="DVCA" secu="VOD" exch="XLON" xdte="2010-11-17" nett/GBX="2.85"
2011-11-16 caev="DVCA" secu="VOD" exch="XLON" xdte="2011-11-16" nett/GBX="3.05"
2012-06-06 caev="DVCA" secu="VOD" exch="XLON" xdte="2012-06-06" nett/GBX="6.47"
2013-06-12 caev="DVCA" secu="VOD" exch="XLON" xdte="2013-06-12" nett/GBX="6.92"
2013-11-20 caev="DVCA" secu="VOD" exch="XLON" xdte="2013-11-20" nett/GBX="3.53"
datezone
A tool to quickly inspect date/time values in different timezones. The result will be a matrix that shows every date-time value in every timezone:
$ datezone Europe/Berlin Australia/Sydney now 2014-06-30T05:00:00
=>
2014-01-30T17:37:13+01:00 Europe/Berlin
2014-01-31T03:37:13+11:00 Australia/Sydney
2014-06-30T07:00:00+02:00 Europe/Berlin
2014-06-30T15:00:00+10:00 Australia/Sydney
The datezone tool can also be used to obtain the next or previous DST
transition relative to a given date/time:
$ datezone --next Europe/Berlin Australia/Sydney 2013-02-19
=>
2013-03-31T02:00:00+01:00 -> 2013-03-31T03:00:00+02:00 Europe/Berlin
2013-04-07T03:00:00+11:00 -> 2013-04-07T02:00:00+10:00 Australia/Sydney
where the left time stamp denotes the current zone offset and the right side is the zone offset after the transition. The date/time indicates the exact moment when the transition is about to take place.
In essence datezone is a better zdump(8).
strptime
A tool that brings the flexibility of strptime(3) to the
command line. While (at least GNU) date(1) has support for
output formats, it lacks any kind of support to read arbitrary input
from the domain of dates, in particular when the input format is
specifically known beforehand and only matching dates/times shall be
considered.
With the strptime tool reading weird dates like Mon, May-01/2000
becomes a matter of
strptime -i "%a, %b-%d/%Y" "Mon, May-01/2000"
=>
2000-05-01
just as you would have done in C.
Note that strptime actually uses the system libc's strptime routine,
and for output the system's strftime routine. Input and output
modifiers will therefore vary between systems.
For a portable parser/printer combination use dateconv as described
above. Its input and output format specifiers are independent of the
C runtime.
Similar projects
In no particular order and without any claim to completeness:
- dateexpr: http://www.eskimo.com/~scs/src/#dateexpr
- allanfalloon's dateutils: https://github.com/alanfalloon/dateutils
- yest http://yest.sourceforge.net/
- pdd https://github.com/jarun/pdd
Use the one that best fits your purpose. And in case you happen to like mine, vote: dateutils' openhub page