I love this little alarm clock so much , I have several throughout my house . pro : \* 24 hour time -lrb- a huge plus for people who have to work shift -rrb- \* nap timer -lrb- I use this feature all the time to wait 15 minute to see if I have correctly treat a hypoglycemic episode -rrb- . you can nap up to 4 hour . \* small and portable con : \* can only set the date and time forward ; you have to scroll through the entire cycle if you have overshoot you value . \* can not turn the back light off -lrb- but it only stay on for about 4 seconds -rrb- \* can not turn the nap timer off \* can not see how much time you have leave on you nap