If, for whatever reason, you want to uninstall Opening Hours module, it can be easily done by following the below steps.
1) Go to Extensions > Extension manager.
2) Click manage on the left side of the screen.
3) Search for "Opening Hours".
4) Select the Opening Hours module (and installer-plugin or languagepacks if installed).
5) Click the uninstall button on top of the screen.
And uninstallation is done!