I found a question regarding the Wedding option in the spell ceremony – What qualifies a creature as being "widowed" for the purposes of Ceremony? – but saw none about the other options.
The description of the ceremony spell (XGtE, p. 151) says, next to the Coming of Age and Dedication:
For the next 24 hours, [something occurs]. A creature can benefit from this rite only once.
That's a bit ambiguous. Does that mean the creature can only benefit from the rite once within the 24 hours to avoid stacking the benefits, or is that once ever?
Best Answer
Once ever.
Once. Not once per day, or once per casting, but simply "once". The meaning of "once" in the English language is clear, and means you can't benefit from it a second time.
If a spell or something can only be used once per day or once per long rest, it says so in the description. The spell ceremony is a rare case where you can only benefit from this spell once ever, because it represents a once-in-a-lifetime event.
Multiple castings of the same spell don't normally stack, so the spell wouldn't need to specify that you can't benefit from two castings at the same time.