We live in an apartment building with a digital thermostat that we don't know how to use and the office is closed. There are 7 buttons. We know what fan, and arrow up and down mean. But how do you adjust the temp? What is the blue button with the white circle (on/off??) What is the square with the lines on the left and a diagonal on the right??? the house with the thermostat seems to make some change in the temperature. and lastly what looks to be a quarter hour of a clock --a timer?