Depending on your setup there are two ways to set up an autotimer (series link), on my setup, using atv 6.1 and kiddacs vskin-hd they are:
Press epg and then
1. press RECORD button and select autotimer from sub menu. This will record that show every time it is on that channel, including repeats shown on that channel.
or
2. press the RED button then select Add Autotimer you are then given a number of options, ie day of week, time span etc it may still record repeats but only if they are shown on the select day and timespan etc