I believe the TDCREATE is the date the drawing was really created....IOW, not the drawing itself, but the Template it was created from. The Windows Creation date isn't always correct either. I just grabbed a random dwg file to see what Windows shows for it, and it has a creation date of April 9, 2020...and this is a drawing I've been working on for about 4 years! According to the AutoCAD TIME command, April 9 is when I last saved the dwg.