You copy the function in your own docs and you make sure that the column names for start & end date are the same. That is all. No packs to install. Simple and straightforward.
When you only use dates and no date -time, it works as any other variation.
Is there support?
If you need support, we can set up online training (1200 Euro per day, group of max 8 people) or you buy support hours as of € 250 per hour running down to half once you buy 24 hrs to be consumed in 3 months.
Projects start as of 10K Euro. This template is for sale.
. The summary is that once you have access to the doc and its content (including the formulas) you can use it as you see fit. How you apply them is your and yours alone, I am not involved. If you have purchased this template, you also do not intend to share the formulas on a commercial basis with somebody else. This I cannot check, it is a matter of courtesy.