It's very important to be careful when writing the dates on cheques or other important documents in 2020, as we must take precaution to write in the full format.
For example, we should write 31/01/2020 and not as 31/01/20, as anyone can change the date of 31/01/20 to 31/01/2000 or any other number. Somebody, who wants to backdate can easily do so. While one could also backdate a 2019 document by writing on it, but, that goes way far into the 1900s.
This can be done on cheques and any important document, so be careful. While in the case of cheques the vailidity is only 3-months, one needs to be careful of other important documents where one needs to write the year in full.