Tired canvassing board adjourns

I am in Dumaguete and following closely the local elections.
It is a day after the May 14 elections, and in the city level,the board of canvassers has already been convenedto canvass the votes based on the election returns from the different polling precincts.
I was surprised that at around 7p.m. the city board of canvassers went home allegedly because there were already tired.
They said the board re-convenes tomorrow morning.
This is a very irregular procedure because Section 231 of the Omnibus election code mandates that the board of canvassers must continuously count the votes from day to day.
The only time they can adjourn is when they await the arrival of the election returns from the precincts.
I have not seen any provision that allows the board to just dismiss themselves, while the certificates of canvass have not been fully counted.
As a matter of fact, the city board of canvassers are mandated to finish their counting within forty eight hours.
How can they finish it now when they went home and agreed to return after twelve hours.
Failure to comply with Section 231 of the omnibus election code constitutes an election offense.