The time is set by pressing one of the buttons located as shown in the figure.

By pressing and holding the "H" button, the required hour of the day is set.
Pressing and holding the "M" button sets the required minutes.
Pressing the "SET" button sets the fast time rounding. For example, if you press the "SET" button when the clock shows the time between 1:01 and 1:29, it will change to 1:00.
