Played 
On a number of sites now, including 5 main current ones, I've used HP Data Protector, one of HP's enterprise-level backup software packages ... depending on who you talk to.
Anyway, because Data Protector, originally called HP OmniBack, was ported over from the UNIX platform it means that most of the configuration can be done by editing plain text files. This includes the schedules, although the schedule text files can often get pretty messy once you've made a few changes. Below are a few backup schedules that have had all the fat trimmed out and don't have anything you don't need in them.
Daily & weekly full at 1830
This job runs a full backup every Monday-Friday at 1830 excluding the first Friday of each month. I usually choose to run a monthly backup on the first Friday of each month so this is a necessity for me.
-full
-every
-day Mon Tue Wed Thu
-at 18:30
-full
-day 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
-at 18:30
-full
-exclude
-day Sat Sun
-at 18:30
Daily differential at 1830, weekly full at 1830
This job runs a differential backup (incr1 in DP) every Monday-Thursday at 1830 and a full backup every Friday at 1830, excluding the first Friday of each month.
-incr 1
-every
-day Mon Tue Wed Thu
-at 18:30
-full
-day 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
-at 18:30
-full
-exclude
-day Sat Sun
-at 18:30
Monthly full on the first Friday of each month at 1830
This job runs a full backup on the first Friday of every month at 1830. It fits in with the schedules above.
-full -every -day 1 2 3 4 5 6 7 -at 18:30 -full -exclude -day Sun Mon Tue Wed Thu Sat -at 18:30