Home standby doesn't happen not very often for me. My last was about a month ago and i was standby from 4z, got a call at 9z for 16z airline. Before that i can't recall it has been that long, but at least 12 months.
I had a 4 day tour this week and the co-pilot (who lives in N Yorkshire) was on 6 days, the first two days he spent at home on standby and his 3rd day we met at Manchester, and he had been briefed the day before for that.
During the winter my average roster has been 14 days, which i consider pretty good.