Typically when writing the short date, we write dd/mm/yy, but this year could cause a problem. Only writing the year as '20' leaves a potential for fraud because there is space where other digits could be added on. For example, 12/01/20 could have '18' added on, so that it reads 12/01/2018. Therefore, it’s probably good practice to use the full form of the year every time you write the date this year.