It only makes a difference if you want to try to do things like your request to subtract one. Subtracting one from a string like '20190801' is impossible. Subtracting one from a number like 20190801 will yield 20190800 and not 20190731. So if you want to work with them as actual dates you will need to convert them to date values. You can then display them using any date format you want, including YYMMDDN8., which will make strings that look like your example.
... View more
