My ST01C works fine for a few days and then resets itself. The clock flashes 12:00am every time it resets and their is no pattern to it resetting. Sometimes it works for 2 days; sometimes 4-5. I reprogram and it repeats itself. Any ideas? Thank you!

The car manual will tell you how to reset the clock. Or contact the dealer OR
go to manufacturer web site for manual download.

If you reset ST01C timer using reset button, then all programs are lost, plus current time of day.
Generally this timer needs to be reset if error message appears and as last resort for troubleshooting problem. Timer does not need to be reset after battery goes bad, all you do is set current time of day, and then program remain inside timer indefinitely (or until timer is reset of goes bad)
If setting current time of day does not work, you use reset button.
For ez programming steps with illustrations:
http://waterheatertimer.org/ST01C-program.html

How to reset ST01C using reset button:
Push and hold ON-OFF button and then push reset button using toothpick or paperclip.
Release reset button but keep holding ON-OFF button until INIT displays.
Then release ON-OFF and 12:00 should be flashing.
If timer functionality does not restore, then try replacing timer battery.
If functionality will not restore, then timer is bad.
This timer does not need electric current for setting timer, so timer display is not dependent on circuit breaker.

If you have a different timer, then add a comment with in-focus photo of timer for possible identification. Most other timers do not require 2-button reset procedure.
http://www.fixya.com/support/r6568559-post_photograph_fixya_questions_answers

Add a comment for more free help

Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

1) If timer worked before and stopped working, then manual says last step is to reset timer.
If timer will not function after reset, then timer is broken.

2) You posted under battery-operated ST01C timer, that comes with 1 year limited warranty.
Open following page to identify timer, read ez instructions, and download on-line manual
http://waterheatertimer.org/ST01C-program.html

3) How to reset ST01C
Hold down on-off button and press reset button
Release reset button.
Keep holding down on-off button until INIT flashes on screen.
Release on-off and 12:00 will flash
Re-program timer using ez steps shown on link above.

Add a comment for more free help.
Also take advantage of fixya expert assistance live.
For a price, expert works with you while you work on timer or any do-it-yourself project.
Fixya is always less expensive than a service call.

I had the same problem. Just random times of the day it would freeze. I followed every step in the manual. Did major fully day unplugged resets. Made sure the Voice Command was not on. Repeated many of these strategies in different order with advisement from Insignia tech. Problem persisted over course of a month no matter what I did. The best solution I found was battering it with my hammer until it was in 100 pieces. It doesnt freeze up anymore. My SONY alarm clock works great.

no-op means 'no operation.

The manual says last resort to revive non-working timer is RESET timer.
This action will delete current day setting and all programming

Hold down ON/OFF and use paper clip to push in reset button for 2 seconds.
Release reset button but keep holding ON/OFF button down until INIT flashes on screen
Then release ON/OFF button and 12:00 should display.

At this point, timer can be re-programmed.
Simple step by step shows on following link:
http://waterheatertimer.org/ST01C-program.html

If timer will not accept programs, or operate after RESET, then timer has gone bad.
ST01C comes with 1 year limited warranty.
Most in-wall timers have same limited warranty.

Replacing timer:
-Advantage of ST01C is timer does not need Neutral wire to operate, and wiring can be simple.
-If you are using ST01C for 3-way switching, then easiest thing is to replace with same timer.
-If you are using timer as astronomic dawn-dusk, then replacements include EJ500, Utilitec 0192773, Aube T1034, T1070, T1072, T1073.
-If you are using timer for 7-day operations then there are numerous options:
http://waterheatertimer.org/Programmable.html#Aube

The ST01C is unnecessarily difficult to program.
And the manual is confusing and unclear.
I wrote a page to help ST01C users who want specific on-off times (not dawn to dusk):
http://waterheatertimer.org/ST01C-program.html
I test and work with timers each day, and I had to fool with the ST01C for an hour or more.

First thing I learned is how to clear programs and start over.
Hold down ON-OFF and press reset button with paper clip.

Next thing I learned is to set programs before setting current day and time.
That way when you have to reset and start over, you are not re-setting current day and time each time.
Set current day and time after programming timer.

Timer doesn't have to be wired into the wall to set programs.

Here's a tip:
Program1 is ON
Program2 is OFF
Program3 is ON
Program4 is OFF

The key is watching the small light bulb icon on display when programming.
When light bulb is dark, that is ON
When bulb is is light, that is OFF

add a comment if you need more help

You posted under ST01C Intermatic timer.
DUSK is the dusk-to-dawn option available with astronomic timers like the ST01C.

If the ST01C is not your timer, add a comment with your timer brand.
I have tested the ST01C and many other timers.

To diagnose the timer, press manual override (on-off button) to see if timer operates Load.
The ST01C will not operate the Load if battery is bad, or if timer has gone bad.

Replace CR2 battery, and then re-program current time and day.
Current day settings are lost when battery goes bad, but the on-off programming remains indefinitely inside timer memory until the reset button is pushed.
To clear timer memory, hold down on-off button and push tiny round reset button for several seconds.

The following link shows the manual and EZ steps to reset timer:
http://waterheatertimer.org/ST01C-program.html
The link also shows other timers in case you have a different brand.

You posted the question under ST01C timer.
This timer will clear all programs if you hold reset in for a few seconds until the screen starts blinking 12:00. The reset button is a small round button that you push with a paper clip.
The ST01C memory for current day can be cleared by removing battery for a couple minutes, but the day-to-day programming remains forever until timer is reset.

Each timer tends to follow the same pattern as described above when there is a small round reset that is pushed with a paper clip >> push, hold for a few seconds, timer resets.

Other timers have a larger button for Reset ... the timers with larger reset button usually require you to hold the clock button and reset button at the same time ... or some other button besides clock has to be pushed at same time with reset. You can try different combinations of buttons and hold both down for a few seconds.

If you reply to this response with your exact model and brand timer, I can look up the specifics for most timers

1) Pull the batteries and replace them, or gently insert a straightened paper clip into the "reset" hole in the back of the clock. The clock will beep.

2) Press the "receive" button" so the clock sets itself. The default time zone will be "EA".

3) Press the "adjust" button untill the time zone is showing (rather than the day-of-the-week).

4) Press and HOLD the "set" button down untill the hours digits start to flash.

5) Now press the "set" button again six times. The time zone characters will flash.

6) Press the "adjust" button untill your time zone appears.

7) Press the "mode" button to return the clock to normal operation.

8) Press the "adjust" button to display the day-of-week.