====== Date and Time ======
To specify the format of the date and time that appears on all SCCP phones in Cisco Unified CME, follow the steps in this section. 

Note For certain phones, such as the Cisco Unified IP Phone 7906, 7911, 7931, 7941, 7942, 7945, 7961, 7962, 7965, 7970, 7971, and 7975, you must configure the time-zone command to ensure that the correct time stamp appears on the phone display. This command is not required for Cisco Unified IP Phone 7902G, 7905G, 7912G, 7920, 7921, 7935, 7936, 7940, 7960, or 7985G. 

For SIP, you must set the timezone value

===== Configuration =====

==== SCCP ====
  * Date format - default mm-dd-yy
  * Time format - default 12
  * Time zone - default 5
<code>
telephony-service
  date-format {dd-mm-yy | mm-dd-yy | yy-dd-mm | yy-mm-dd} 
  time-format {12 | 24}
  time-zone <number> 
</code>

==== SIP ====
  * Time zone
    * default 5 = Pacific Standard/Daylight Time -480mins
  * dst auto-adjust
    * auto adjustment of daylight saving
<code>
voice register global
  timezone <number>
  date-format [d/m/y | m/d/y | y-d-m | y/d/m | y/m/d | yy-m-d]
  time-format {12 | 24} 
  !
  dst auto-adjust  
  dst {start | stop} month [day day-of-month | week week-number | day day-of-week] time hour:minutes 
</code>