Birthday Baths

Wasting water is a sin greater than all others, on all days except one.

As any inhabitant of Saraya would say, water wasted is life lost, but they do make one special half-exception, birthdays. These people celebrate the day of their bath with a thorough cleaning that contrasts with the rough, barely wet sponge they can afford during any other day of the year.

History

Though the actual origin is not known to any folk who still live, this tradition evolved from a time where water wasn't so scarce and life wasn't so hard. Back then, the tradition was much more widespread and involved. Anyone who knew the person had their birthday could douse them with a bucket of water thrown at them at any time throughout the day, and any close relatives or partners often did it more than once!
Such wastage no longer exists, but the lines can be traced between allowing some extra water to be used on a single special day to this old tradition of wet pranks.

Execution

Stars, you stink, child. Your birthday must be coming up...

One no longer needs to be in constant worry of getting drenched in water on their birthday, rather they look forward to it as a day they can indulge in a cold bath prepared by their family just for them. Of course, the water is reused, often for livestock, but it is significant enough that the water is only used by them, as a treat for another hard year of life. As is usual, the richer the person and their family, the grander the bath.
Once they complete their bath, which often takes at least an hour of indulgence, they spend the rest of the day at ease with their family. They eat and partake of the fruits of their labour and simply enjoying the company while trying to forget about any worries.