Summary

When creating a lab, filling in the "slot selection opens" time manually without the : creates interesting behaviour: hitting the "Create lab" button at the bottom simply refreshes the page, no message whatsoever. Now the time is suddenly formatted correctly, and hitting the button again does create the lab.

Steps to reproduce

1. Go to the lab creation page.
2. Fill out everything correctly.
3. Choose a time for the "slot selection opens at", but fill out the time like 0900 instead of 09:00. This works fine on the other date/time pickers (lab start + end time).
4. Hit "Create new lab".
5. Observe that the lab was not created, but also no error shows.
6. Hit "Create new lab" again without making any changes. Now it works