Add more options for recurring dates

Problem/Motivation

The current functionality for recurring dates is somewhat basic. It would be good to offer some more advanced options for specifying recurring dates.

Proposed resolution

Offer the ability to specify more granular rules, such as:

Annually

• w years
• x day of month y
• the xth y-day of month z
• the last y-day of month z

Monthly

• x day
• the xth y-day
• the last y-day

Weekly

• every xth week
• choose days of the week

Daily

• every xth day