Aging report formula that does NOT use 'TODAY' but rather March 6 2020

[Pasco2018]

Hello, I have created a 13 week aging report for a 13 week cash flow.  I am currently using =IF(AND(TODAY()-$C486<=21,TODAY()-$C486>14),$D486,0) formula, does anyone know a formula that can be used for aging reports, but does not use "TODAY' as the starting point to age?  I have a rather large spread sheet and I cannot get my reports done in one day so when I come back to it the next day or in a few days, some of my values in the columns have moved by one column.  Is there a way I can say age from March 6th 2020, not today but from a static date.

Thank you

Lorna

[#2]

@Pasco2018 -

If I understand correctly, I offer two options:

Option1 uses a helper field:

=IF(AND($A$2-D2<=21,$A$2-D2>14),TRUE,FALSE)

Option2 does not:

=IF(AND(DATEVALUE("3/6/2020")-D2<=21,DATEVALUE("3/6/2020")-D2>14),TRUE,FALSE)