As other computers can have other default date format (BRITISH, FRENCH, GERMAN,..) you better do as Mike suggests. Just a little correction, DATE(y,m,d) will be DATE(2020,12,7) for 7th december 2020 and not DATE(2020,7,12), which is for 12th July.
And thanks for refreshing my memory about the curly brackets format. It's one of the things, where VFP goes another route as all other databases, which usually take a date in some string format. Unfortunately there also are differences and no common format. You have to be very cautious about settings of the different IDEs, it can really change between MDY or DMY, if not even YMD, The DATE() function always needs parameters in the order of YMD, year, month, day. And today is DATE().
So shifting today to next week can be done by using REPLACE field WITH DATE()+7 FOR field = DATE() and shifting last week to today is REPLACE field WITH DATE() FOR field=DATE()-7.
Chriss
PS: You might want to ensure the FOR condition is sufficient, because, in a table as large as you describe, it might as well be you only want to shift some of the records to next week, for example depending on a status field.