Defining time in EU Regulations

A question that I often get asked is " What does '1 month' refer to when used in the context of Subject Access Requests in the GDPR?".

It was something that I also found confusing early on when learning about the regulation. Did it mean 30 days? 31 days? a calendar month? or something else? What about February and leap years? Why couldn't it be clearer in the regulation's text?

Well I found my answer here on LinkedIn. Someone kindly pointed me to the document linked below. (Sorry I can't remember who it was).

So I thought I would post it more prominently for the benefit of those still scratching their heads in confusion.

See article 3 (2.d)

"if a period includes parts of months, the month shall, for the purpose of calculating such parts, be considered as having thirty days".