Words For Frequencies Less Than An Hour

I'm writing a scheduling program and need to show frequency options ranging from once a minute to once a year. Anything over an hour is pretty simple, but I'm looking a formal term for frequencies under an hour.

Every...   | Term
Year       | Annual
6 Months   | Semi Annual
3 Months   | Quarterly
1 Month    | Monthly
Week       | Weekly
Day        | Daily
Hour       | Hourly
30 Minutes | Semi Hourly (?)
15 Minutes | Quarter Hourly (?)
10 Minutes | Decminutely (?)
5 Minutes  | Pentminutely (?)
2 Minutes  | Biminutely (?)
Minute     | Minutely (?)

If anyone has an idea for a better SE forum that this should be posted on please let me know

There are the expressions half-hourly and quarter-hourly, but every 30/15/10/5/2 minutes is clearer and avoids misunderstandings.

I would definitely recommend sending this to the User Experience SE.

For clarity, I would consistently use the "every n units" format: "every year", "every 6 months", "every quarter", etc.