If you're not in the eastern timezone change the -5 value below 
to reflect your timezone (california/western/PST time would be -8)
If you're in europe change usa to eu, if you're elsewhere either don't use 
the summer-time recurring command or type clock summer-time recurring ? to 
see how to do a custom daylight savings/summer-time automatic clock 
adjustment.  
conf
sntp unicast client enable
sntp unicast client poll 
sntp server 10.x.x.x poll
clock source sntp
clock timezone -5 
clock summer-time recurring usa
exit
credit to virtual dave from which I got most of the core commands: http://wiki.xdroop.com/space/Dell/Power+Connect/Time+Configuration
I have a bash script for retreveing the port to mac address table from the switch via telnet (I personally use it under cygwin), you will have to do some edits to it, and is meant to work with dell power connect 54xx switches, though it can be edited slightly to work with dell powerconnect 55xx switches. The script is here: pc-54xx-ports-pub.sh and will output the information to a nice csv file.
 if you want to get the table via snmp you can use 
snmpwalk -v 1 -c public 10.x.x.x .1.3.6.1.2.1.17.4.3
 more details at 
Virtual Dave
if you're using windows you can get snmpwalk at 
Net-snmp.org