Octet string that identifies the GMT timestamp of last
successful SET PDU from this CLI user.
field octects contents range
----- ------- -------- -----
1 1-2 year 0..65536
2 3 month 1..12
3 4 day 1..31
4 5 hour 0..23
5 6 minutes 0..59
6 7 seconds 0..59
7 8 deci-sec 0..9
* Notes:
- the value of year is in network-byte order