Type Alias: DurationPricingUnit

type DurationPricingUnit = z.infer<typeof DurationPricingUnit>;

The units a BasePriceAction.per may name — the tier modal's "Duration" select (PLA-233 #2), i.e. the SECOND axis in "Per attendee per hour".

Deliberately a narrow subset of PricingUnit, not the whole enum:

hour / day / night are the only units every quantity resolver in the repo answers as a duration (see getBookingQuantity in server/bookings/pricing-glue.ts).
month / year are excluded even though they read like durations: the bookings resolver answers them with capacity_units, i.e. a COUNT. Allowing them here would let person × month multiply party size by party size — the axis-squaring this type exists to prevent.
unit / person / flat are counts, not durations. A second count axis has no product meaning ("per attendee per attendee").