Q: Is there an app or program that will allow entry of irregularly recurring events on the calendars for the iPhone, iPad or Mac?
A: Although this depends partly on exactly how “irregular” you want your events to recur, much like the Reminders app, this is one of these situations where the iOS user interface provides for much more limited options than are actually possible.
Setting a repeat interval on the iPhone, iPod touch or iPad provides only a very limited list of fixed options, with no further customization available. Specifically, you can set the repeat interval to Every Day, Every Week, Every 2 Weeks, Every Month or Every Year, and that’s about it.
Fortunately, the Mac OS X Calendar application provides considerably more flexibility in this regard, with options for custom daily, weekly, monthly and yearly repeats, including intervals based on only certain days of the week or month, the Nth weekday of a given month or only certain months out of each year.
Even though you cannot actually set these options in the iOS Calendar app, anything you set here (or in any other third-party app) will actually be handled properly by the iOS Calendar, which will even show the custom repeat information for the event.
Other desktop and web calendar solutions such as Microsoft Outlook and Google Calendar offer similar options for creating recurring events, all of which will be handled by the iOS Calendar in much the same way.
Further, numerous third-party apps such as Calendars by Readdle and Pocket Informant also provide the ability to set custom repeat information directly on the iOS device; although they are basically limited to the same type of repeat settings that can be configured in the OS X Calendars app, they may be viable solutions if you find that you do most of your calendar management on an iOS device rather than a Mac.
Unfortunately, these semi-regular repeat intervals are about as sophisticated as most applications get, and if you’re looking for something that is completely irregular and follows no standard pattern, you’re basically going to be faced with handling this at least somewhat manually. One option is to simply create a standard appointment on your Mac or Windows PC and then copy and paste it to any additional dates as necessary.
Alternatively, if your events follow a semi-regular schedule with only some exceptions, you can begin with one of the custom repeat options as a starting point, and then simply delete or move any events that don’t fit that standard pattern. The Calendar app is capable of handling such exceptions, effectively breaking them out from the repeat interval without affecting any subsequent events.
For example, lets say you had a meeting that occurred every Monday at 9 AM, Wednesday at 10 AM, and then every second Friday at 9 AM. In this case, you could create a weekly repeat for Mondays, Wednesdays and Fridays at 9AM, and then simply adjust each of the Wednesday appointments to 10AM and delete the appointments every other Friday. Or, alternatively, you could simply create three separate weekly recurring appointments—weekly for the Monday meetings, weekly for the Wednesday meetings, and bi-weekly for the Friday meetings.