Yeah pretty easy to do once you know how.
here's an excerpt from one of my scripts that checks if its the first day of any month.
:set date [/system clock get date]
:set time [/system clock get time]
:set month [:pick $date 0 3]
:set day [:pick $date 4 6]
:set year [:pick $date 7 11]
:set hour [:pick $time 0 2]
:set minute [:pick $time 3 5]
#Show variables for testing
:log info "The time is $hour:$minute and the date is $day / $month / $year"
That'll give you all the details you could need each stored in their in their own variable and print it out in the log (so you can see what is generated)
You can then use something like this
:if ([$month] = "jan") do={ }
:if ([$month] = "feb") do={ }
:if ([$month] = "mar") do={ }
:if ([$month] = "apr") do={ }
:if ([$month] = "may") do={ }
:if ([$month] = "jun") do={ }
:if ([$month] = "jul") do={ }
:if ([$month] = "aug") do={ }
:if ([$month] = "sep") do={ }
:if ([$month] = "oct") do={ }
:if ([$month] = "nov") do={ }
:if ([$month] = "dec") do={ }
To do something based on what month it is.. or modify to suit your needs.