> ## Documentation Index
> Fetch the complete documentation index at: https://docs.totemdigital.ro/llms.txt
> Use this file to discover all available pages before exploring further.

# Programming the ZYT16G timer: clock and on/off groups

> How to unlock the ZYT16G-2a/3a timer keypad, set the clock, and program up to 16 on/off groups for the output circuits, step by step.

Programming the ZYT16G-2a/3a timer takes three stages: unlock the keypad, set the clock, and set the on/off groups for each output circuit.

## Unlocking the keypad

First, **press the RESET/RECALL key four times in a row**: the lock symbol disappears and the keys can be used.

<Note>
  If no key is pressed for 30 seconds, the lock symbol appears again and no further input is accepted. Repeat the unlock procedure.
</Note>

## Setting the clock

Press the **HOUR**, **MINUTE**, and **DAY** keys to adjust the hour, minute, and day to the current time.

## Setting the timer

<Steps>
  <Step title="Press the TIMER key">
    Enter the first timing group (the display shows **1 ON**).
  </Step>

  <Step title="Press the DAY key">
    Set the switch-on day (every day, 5 days, 6 days, a different day each time, etc.).
  </Step>

  <Step title="Press the HOUR and MINUTE keys">
    Set the switch-on time (hour, minute).
  </Step>

  <Step title="Press the AUTO/MANU key">
    Select the output: "1", "2", "1&2", "2&3", "1&3", or "1&2&3".
  </Step>

  <Step title="Press the TIMER key">
    Enter the first switch-off timing group (the display shows **1 OFF**).
  </Step>

  <Step title="Press the DAY key">
    Set the switch-off day (every day, 5 days, 6 days, a different day each time, etc.). Make sure the switch-off day matches the switch-on day.
  </Step>

  <Step title="Press the HOUR and MINUTE keys">
    Set the switch-off time (hour, minute).
  </Step>

  <Step title="Press the AUTO/MANU key">
    Select the output: "1", "2", "1&2", "2&3", "1&3", or "1&2&3".
  </Step>

  <Step title="Repeat steps 1 to 8">
    Set between 2 and 16 on/off time groups. If you do not need all 16 groups, press the RESET/RECALL key to clear the remaining groups to "--:--" (not 00:00).
  </Step>

  <Step title="Press the TIMER key repeatedly">
    Check that each on/off group is correct. If you find an error, press RESET/RECALL and repeat steps 2 to 8.
  </Step>

  <Step title="Press the AUTO/MANU key repeatedly">
    Set the on/off indicator to the current state ("on" or "off"), then set it to the automatic position (AUTO).
  </Step>

  <Step title="Press the CLOCK key">
    Exit timer setting mode and return to the clock display.
  </Step>
</Steps>

<Tip>
  If the timer loses its settings or stops working, see [Battery replacement](/en/timere-electronice/zyt16g/inlocuire-baterie).
</Tip>


## Related topics

- [ZYT16G-2a/3a timer: description and technical specifications](/en/timere-electronice/zyt16g/prezentare.md)
- [ZYT16G timer not working: replacing the AA battery](/en/timere-electronice/zyt16g/inlocuire-baterie.md)
- [Electronic timer user manuals by Totem Digital Romania](/en/timere-electronice/prezentare.md)
- [Programming the CN101 Timer: Clock and Weekly Programs](/en/timere-electronice/cn101/programare.md)
- [CN101 Timer: Description and Full Technical Specifications](/en/timere-electronice/cn101/prezentare.md)


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