wrapper/qualifier for crontab entries, tests for date conditions like "first Monday" and returns True(0) or False(1) exit status
multiple conditions are considered an OR test: if any are true, is_it will return True(0)
embed is_it in your crontab entry e.g.:
1 0 * * * [ "is_it -c f -d mon" ] && logger "It's 12:01AM on the first Monday of the month"
(is_it must be in the path or provide the full path in the crontab line)
Usage: is_it -c count -w weekday [-v] [-t YYYYMMDD] [-h]
Test whether this is the "c'th" weekday "w" of the month.
-c, --count recurrence count of the month e.g. "f" or "first", "l" or "last", 1,2,3,4,5
multiple entries can be listed as a sequential range e.g. 1-3 or a non-spaced comma separated list e.g. 2,4
-w, --weekday day of the week e.g. 0 to 6 (Sunday to Saturday), "Mo," "Mon," "Monday" (case insensitive)
multiple entries can be listed as a sequential range e.g. tue-thu or a non-spaced comma separated list e.g. mo,we
-v, --verbose echos output e.g "it is not the last thursday of the month" (default is silent)
-t, --test pretends today is YYYY-MM-DD for testing purposes
-h, --help displays this help and exit
Exit status:
0 date test is positive
1 date test is negative or is_it otherwise failed\
examples:
is_it -c first -d mon # first Monday of the month
is_it -c 1,3 -d Saturday # first or third Saturday of the month
is_it -c l -d fr # last Friday of the month
Use cron to control monthly recurrence. For example, to run a task on the last Friday of each quarter:
59 23 * 3,6,9,12 * [ "is_it -c l -d fri" ] && logger "It's 11:59PM on the last Friday of the quarter"