Put in everyone's working week once and it fills itself in, or draft a rota and publish it when it's ready. Holiday is asked for, approved and counted down, all in one place.
Grey: usual hours, filled in every week. Coloured: the rota.
People ask for a day, a few days, a morning or a couple of hours. Whoever approves gets a notification with who else is off and what's left, and says yes in a tap. Their allowance counts itself down.
Can't make a shift? Offer it to a colleague or anyone, and it moves when they take it.
Allowances in days or hours, carried over if you like. Self-employed? Unlimited, still recorded.
Approvers see who's already off, and get a warning before too many people are away at once.
If everyone works Monday to Friday, set it once and you're done. If your rota changes, put it in whenever you like: draft it, copy last week, move things about, and publish when it's right. Only then does everyone see it, and hear about it.

Owners and admins choose how holiday works, who approves it and who hears about it.
January to December, April to March, or whenever yours starts. Allowances start again on the day.
Count holiday in days or hours, for the whole company or person by person.
Everyone with the permission, or a named approver per person, such as their manager.
Pick the people who get a notification every time someone asks for time off.
Holiday, sickness, unpaid leave, training or your own, each counting towards the allowance or not.
Early, Late, Night, Site: save your usual shifts and fill a rota in a few clicks.
Warn approvers when too many people would be off on the same day.
Let people swap shifts straight away, or only once someone approves.
Every Orkello app shares the same people, the same bell and the same search.