I need to reset the clock on the machine.

The 50015 has a countdown feature.
Manual says you get to the correct mode, then press the clock button, then press and hold RCL-CD for 3-5 seconds ... then CD will flash in lower left corner.
If timer does not perform this function, then try the reset button ... push and hold reset for 10 seconds, then reprogram ... if functions are not restored, then timer might be defective.
More info on product and product manual appear following link:
http://waterheatertimer.org/Outdoor-timers.html#50015

There are two ways to set the clock on your coffee maker. 1- When you initially plug in the coffee maker, the unit will beep and "12:00" will flash on the LCD display for a few seconds. Press immediately the h/min button (o) to set the current hour. If "12:00" starts to flash, press the PROG button (n) for a few seconds until the "12:00" flashes again. Then press the h/min button (o) to set the current hour. There are AM and PM indicators on the top right side of the LCD screen. To set the current minutes, press the PROG button (n) and then press the h/min button (o) until the correct minutes appear on the LCD display. After 5 seconds, the unit will beep and the time will stop flashing. 2- At any other time, you can set the clock or change the set time by pressing and holding the h/min button (o). The unit will beep and "12:00" will flash on the LCD display. Use the h/min button (o) to set the current hour. There are AM and PM indicators on the top right side of the LCD screen. To set the current minutes, press the PROG button (n) and then press the h/min button (o) until the correct minutes appear on the LCD display. After 5 seconds, the unit will beep and the time will stop flashing. Notes: Your clock has now been set and will continue to keep the correct time, even after the coffee maker has been shut off. Unplugging the coffee maker or a power failure will reset the clock to 12:00 AM. Repeat the instructions above to reset the clock

Source : Krupsusa.com
Link to manual : http://product-support.groupeseb.co.uk/Download/Pdf/366/km730

easiest way to set clock time. Remove AA battery's if installed.
Unplug Clock from AC. Wait a few seconds. Then replug clock into AC power. Clock will now flash 12:00. Press hours button until correct time is set PM has led on AM has Led off. Set minutes to correct minutes. Then press alarm reset / power/mode button. Wait a few seconds and display will show correct time. Now you can put the AA batteries back in.

Here's the thing: When you change the batteries, the radio thinks you need to reset the time, even though the time has been preserved and is correct even after you change the batteries. Here's what you do: Pretend you need to reset the time. With the radio off (recommended), press and hold the "Band" button with the "set" notation underneath it. The hour will flash. "Reset" the hour by using the tuning buttons, as you would if the radio were new, and then change it back to the correct hour. Press the "Band" button again and repeat the process for the flashing minute display. Press "Band" again to end the process. You will have successfully fooled the H201 into thinking that you have reset the time, and the time display will have stopped flashing. (This does not appear to work if you do not actually pretend to change the hour and minute and just keep pressing the "Band" button -- you have to go through the procedure as though you were actually changing the time.)

To set the clock. You must set the clock once so that the system announces the correct day and time with your messages. After this, if you subscribe to Caller ID, the system will automatically reset the clock each time new call information is received.

Press PLAY/STOP to exit at any time while
setting the clock.
1 Press and hold CLOCK until the Message Window displays C, and the default day is announced.
2 To change the day setting, press and release MEMO/REPEAT or ANNC/SKIP until the correct day is announced.
3 Press and release CLOCK. The current hour setting is announced.
4 To change the hour setting, press and release MEMO/REPEAT or ANNC/SKIP until the correct hour is announced.
5 Press and release CLOCK. The current minutes setting is announced.
6 To change the minutes setting, press and release MEMO/REPEAT or ANNC/SKIP until the correct minutes setting is announced.
7 Press and release CLOCK. The current year is announced.
8 To change the year setting, press and release MEMO/REPEAT or ANNC/SKIP until the correct year is announced.
9 Press and release CLOCK. The new day, time, and year are announced.
To check the clock, press and release CLOCK.
If you need futher instructions for your answering machine you can download a copy from:
http://phone.manualsonline.com/manuals/mfg/att/1738.html
Please rate this solution. Thanks..

Setting the Clock
You’ll need to set the clock so that it can
announce the day and time that each
message is received. Press Play/stop to exit
Setting the Clock at any time.
1 Press and hold Clock until the
Message Window displays C, and the
default day is announced.
2 To change the day setting, hold down memo/repeat
or ANNC/Skip until the
correct day is announced. Then
release the button.
3 Press and release Clock. The current
hour setting is announced.
4 To change the hour setting, hold down memo/repeat
or ANNC/Skip until the
correct hour is announced. Then
release the button.
5 Press and release Clock. The current
minutes setting is announced.
6 To change the minutes setting, hold
down memo/repeat or ANNC/skip until the
correct minutes setting is announced.
Then release the button.
7 Press and release C. The new day
and time are announced.
To check the clock, press and release
Clock.
NOTE: In the event of a power failure,
see the instructions on the bottom of the
unit to reset the clock.
Record a memo /
Repeat all or part of a message


I hope this helps! here is the URL to the information provided

http://telephones.att.com/docMgt/public/art/162/1717_manual.pdf

You need to hold down both the reset and the select buttons until the clock starts flashing. Then push the select button to adjust the hour. Then push the reset button to make the minutes start flashing, push the select button to adjust the minutes. Once you have the time set correctly, push the reset button one more time. You should be done.

This is due to the base unit losing power and needs the clock resetting.
The handsets retain their clocks under battery power so this is a little misleading.

To reset the base unit clock:
- press the OK key
- press the 'down' arrow twice until "DATE/TIME" is displayed.
- press the OK key again, this will display the year. Enter the correct year on the handset numeric keypad and then press OK. (Only the last two digits of the year need to be entered).
- The date is then displayed in MM/YY format, enter the correct date on the handset numeric keypad and then press OK.
- The time is then displayed, enter rhe correct time on the handset numeric keypad and press OK.
- The handset then beeps and displays "SAVED".
- Press the "C" button and replace the handset on the base unit.

The base unit should now stop flashing "CL".

Set the Clock
You must set the clock once so that the
system announces the correct day and time
with your messages. After this, if you
subscribe to Caller ID, the system will
automatically reset the clock each time new
call information is received.
Press Pto exit at any time while
setting the clock.
1 Press and hold Cuntil the Message
Window displays C, and the default day
is announced.
2 To change the day setting, press and
release ror auntil
the correct day is announced.
3 Press and release C. The current
hour setting is announced.
4 To change the hour setting, press and
release ror auntil
the correct hour is announced.
5 Press and release C. The current
minutes setting is announced.
6 To change the minutes setting, press and
release ror auntil
the correct minutes setting is announced.
7 Press and release C. The current
year is announced.
8 To change the year setting, press and
release ror auntil
the correct year is announced.
9 Press and release C. The new day,
time, and year are announced.
To check the clock, press and release
C.