Ask HN: how much time did you *really* spend on that "Show HN: My weekend hack"

This is a genuine question/curiousity that I have. I frequently come across "Show HN" submissions that claim to have done it over the weekend. But looking at the apps makes me wonder if it really just took a weekend. Wondering if ppl would share the actual time taken to build an MVP/app whatever.

I do understand that many CRUD apps can be hacked over a weekend. But some of the mor real world stuff that is shared, I highly doubt it. or is it ?