Tap center to switch from time to date. The time and date is shown as balanced ternery in a tic-tac-toe field. For time that means first row is for hours, the second one is for tens of minutes and the last one for single digit minutes. For date, first row is for month, second one is for tens of day in month and the last one is for single digit day in month. For each row the first column represents 9, the second one 3 and the last one 1. If there is a 0 in a cell, then you should add the corresponding value, if it is a X, then you should substract the corresponding value. In this way you calculate the values for each row.