Hot water tank, should I use a timer or boost?

Hi all,

Just moved into a new place and the hot water system has a weird timer that we haven't figured out yet.

We are wondering if it is cheaper to use the boost function which will run for an hour and automatically shut off (or we turn off manually after 30 mins) or if we should use the timer function to get hot water overnight for the morning.

We don't have economy 7 so there's no advantage of cheaper electricity at night so we are just wondering about power consumption. The hot water is not connected to the heating as that's electric.

Any help would be appreciated.