Workplace clock

There seems to be no-end of clock-based gimmicks, so I'll throw a thought into the mix: a pair of clocks for the workplace, tailored for employers and employees. The clock for employers runs fast in the morning and slow in the late afternoon; the clock for employees runs slow in the morning and fast in the late afternoon. Both clocks would be in sync with normal clocks outside of these periods.

An employee could place such a clock in their cubicle, justifying to themselves arriving late and leaving early. The employer could place such a clock on the wall to encourage earlier starts and latter finishes.

It might be better to sell just the clock mechanism, allowing it to be matched with any set of face and hands. It would also be useful to have a control for the extent of the fastness/slowness.