The "Interval" type Time Trigger options currently allow triggering on "day X every Y months", "Nth Weekday of the month", etc. Each of these options could be made much more flexible if a simple "Days Offset" field was added that offset the calculated date. The field could be a positive or negative integer, and could default to 0 (would result in current behavior).

The scenario in which this would be useful is one where events occur relative to one of the currently definable days.
eg: Microsoft release patches on the 2nd Tuesday of each month. This event can be set up in the Interval window using:

• Interval: Specific days in the Month
  
• Every: 1 Month
  
• 2nd Tuesday

However, there are several events that may occur RELATIVE TO but not ON this date: Dev environment may be updated the following day, and the Production environment may be updated 4 days later. I'd like to automate an email to be sent out 3 days before the 2nd Tuesday to give a week's notice to end users in Production, and on the morning of each of the update days. Right now, we need to manually schedule several events every month in advance for the whole year. (NOTE that selecting "2nd Wednesday in the month" is NOT necessarily the same as "day after 2nd Tuesday" - if the first day of the month is a Wednesday, then the day after the 2nd Tuesday in the month is the *3rd* Wednesday.)

Having a "Days Offset" would add lots of flexibility to the current options. As another example, selecting "Last day of month" with "Days Offset" of -1 would select the 2nd last day of the month.

I think this would be a simple and very useful enhancement.