From CubicleBot: What if you could swap out the clock at work with one that speeds up 20% at 11:00am and slows down 20% every day at 11:48am—giving you 12 extra minutes of lunch in the process?
Think about it—at 11:48 the clock will read 12pm, i.e. lunchtime. When you return at 1pm the clock will be back in sync.
All you need is the materials listed after the break and a boss without a watch or a cellphone.
(x1) Standard wall clock
(x1) Adafruit DS1307 Real Time Clock Kit
(x1) Arduino (w/ATMEGA168 DIP chip)
(x1) Extra ATMEGA168 chip with Arduino bootloader installed (see last step)
(x2) BC547 PNP transistors
(x2) BC557 NPN transistors
(x1) 28 pin socket
(x2) 22pF capacitors
(x1) 16mhz crystal
(x1) 1K resistor
(x1) 7805 regulator
(x1) 4 pin socket
(x1) 9V battery and connector
Granted, 12 minutes doesn’t seem like much, but it ads up over time. Plus, it just might be short enough that the boss might not notice.
Check out Instructables for the full build details.