I have numerous D-Link DGS-1500-28 switches with firmware 1.00.013, 1.10.005 and 2.10.002 on it, and there are no visible option to set up date/time via web- or telnet-interface.
Device uses date/time in logs, but there is no idea, where it obtains it from: now it is different days in 2009 for 1.00.013, in 2011 for 1.10.005 and in 2012 for 2.001.006. The date showing is even not 01/01/YYYY + system uptime, as it could seems to be.