Events and Users are created from the admin UI.

For each Event we generate a bit mask of the 30min intervals that it occupies. For each day we need 48 intervals (0:00-0:30, 0:30-1:00, ... , 23:30-0:00), so the mask will be 48 bits.

Then for each User we can bitwise OR all assigned events for a day and generate a "busy" mask, marking all intervals that they are busy. To check if a new Event conflicts with that User we can then bitwise AND with the busy mask. If the result is not 0, it means there is a conflict.

Additionally, each User has an availability mask which is another bit mask marking the times the User is available (e.g. 9:00-17:00). This is used in a similar way to further filter down the eligible Users.

When an Event is created there is an attempt to assign it to a User. If no User is available for that day and time, then it stays in the database unassigned.

When a User is created (or updated), the assignment algorithm runs again for any unassigned Events, possibly assigning them to the new User.

• Events can't start or end at more precise times that 30min intervals
• Events can't span multiple days
• No timezones support