Getting access to TISS calendar from personal calendar tools

i have unique time schedule for myselves like work roster , university events or personal plan.but some times it's hard to manage them desperately.also i don't have access to the internet all the time.and TISS calendar is changing week by week.so i want to have my TISS calendar in personal calendar even though i'm offline.

How to export events from TISS

I would like to export certain dates from TISS, namely from the courses I'm interested in (not all of them in my favorites). Then I can import them in external applications, for example into Google Calendar.
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