That's the problem. This package is very similar to Microsoft's checkpoint package which is based on Microsoft's MRAN snapshots, and this package also uses MRAN

That's the problem. This package is very similar to Microsoft's checkpoint package which is based on Microsoft's MRAN snapshots, and this package also uses MRAN. The article explains the difference is that this package allows you to specify the date in the code itself, whereas checkpoint is used to set a whole installation to a specific date. But this is no advantage as it means code will stop working if the groundhog package changes, whereas with checkpoint a paper could just say 'use packages as of date x'.