Dates versus volunteer slots

MojoSignUp has two layers of schedule. An instance is a date (and optional time) when the event happens. A slot is a named choice on that date: a volunteer shift, a conference time, or a dish to bring. Most events need only instances. Slots exist for the cases where “I am coming on Tuesday” is not specific enough.

Use instances only

Choose instances alone when every registrant is doing the same thing:

• A parent meeting on one evening
• A six-week class that meets every Thursday
• A workshop with a single start time and a room capacity

People register for the instance. Capacity on the instance is the number of seats. Recurrence can generate the dates so you do not type each Thursday by hand. Time zone on the sign-up keeps wall-clock times stable across daylight saving changes.

Add slots when people must pick a role or item

Add slots when the date is shared but the jobs are not:

• Concession stand: 5–6 p.m. grill, 6–7 p.m. register, 7–8 p.m. cleanup
• Potluck: salad, main, dessert, drinks, plates
• Teacher conferences: 15-minute windows across one afternoon

Each slot has a title, optional description, optional start and end time, and its own capacity. A slot with capacity 1 is a single assignment. A slot with capacity 4 is a team of four on the same job.

Slot templates

If the same set of jobs repeats every Saturday, save them as a slot template and apply the template when you create instances. Changing a template later does not rewrite dates that already exist; apply it when you add the next batch of instances.

Templates are the difference between “I rebuilt concession shifts twelve times” and “I reuse Concession Default.” Name templates after the work, not the date.

How registration behaves

With instances only, the public page asks the person to pick a date. With slots, they pick a date and then a slot. Capacity is checked on the thing they chose. If the 5 p.m. grill shift is full, the 6 p.m. shift can still be open. That is the whole point of slots.

Do not model two different events as slots on one instance. A bake sale and a car wash on the same Saturday should be two sign-ups, or two instances, so descriptions and locations stay honest.

A simple rule

If you would put it on a calendar as one block, it is an instance. If you would write it on a clipboard as a row of names next to a job, it is a slot. Start with instances. Add slots only after the first draft of the event is saved. You can attach slots to an existing instance; you do not need to recreate the sign-up.

Next: set capacity so full shifts stop taking names, then share the page.