L1 + R3 turns on mouse mode
While in mouse mode, right joystick moves mouse cursor and L2 and R2 act as left and right mouse buttons.
Click on the time in the server info area (top right unless you've moved it elsewhere)
The time alternates as you click it between local time (LT), server time (ST), and Eorzea time (ET).
L1 + R3 again to turn mouse mode off once it's set as you want.