Obtain the current time in HH:MM format by querying the device's current time. Get the given wall clock's time as HH:MM by looking at the wall clock. Determine if the clock is fast or slow by comparing the clock's time to the device's time. Determine if the clock is fast or slow by comparing the clock's time to the device's time. Calculate the actual time by adding 15 minutes to the clock's time if the clock is slow. Calculate the actual time by subtracting 15 minutes from the clock's time if the clock is fast. Calculate the actual time if the given time is a quarter past an hour: Subtract 15 minutes from the given time if the clock is fast. Add 15 minutes to the given time if the clock is slow. Display the actual time based on the above steps.