How to change date & time in Solaris, Linux, HP-UX and Netapp?

Changing date/time in Solaris, Linux, HP-UX and Netapp is one command step as long as used with correct syntax.

For Solaris:

# date
Thu Aug 27 00:22:37 SGT 2009
# date 0827002509
Thu Aug 27 00:25:00 SGT 2009
# date
Thu Aug 27 00:25:02 SGT 2009

For Netapp:

# ssh filer01 date
Thu Aug 27 00:20:11 SGT 2009

# ssh filer01 date 0827002509
Error: 27 is not a valid month of the year. Range is 01-12.
usage: date [-u] [[[[CC]yy]mm]dd]hhmm[.ss]]
       date [-u] -c
       date [-f] -c initialize

# ssh filer01 date 0908270026
Thu Aug 27 00:26:00 SGT 2009

# ssh filer01 date
Thu Aug 27 00:26:03 SGT 2009