Monthly schedule maintenance

[zab]

Hello

I'm going nut over dates again.

I need to do a "simple" monthly maintenance schedule.

First table is the hardware with description, picture etc.

Second table Line_Items shows as a portal in the hardware table

this is where the maintenance is selected. It has 5 visible fields

Maintenance description - Starting month - Ending month - Frequency - Next maintenance

(Frequency choices = weekly, bimonthly, monthly, trimester ... yearly)

I need to figure the month of the next schedule maintenance to build a monthly report.

The report find criteria is the Next Maintenance field.

Exemple: we're in november:

--description ------start month ---End Month---frequency-- Next Maintenance

Clean something - march - december - monthly = 11

Change something - december) - april - bimonthly = 12

oil something - October -may - semesters = 1

Since I'm dealing only with months, do I have to use complete dates?

I'm not sure how to convert month 14 into month 2 if I don't use date.

Dates gives me a headache

Any help or link to solution would be appreciated.

Thank you

[comment]

I need to figure the month of the next schedule maintenance to build a monthly report.

I am not sure I understand the task you describe. Could you explain, step-by-step, how you arrived at the answers in your examples?

I'm not sure how to convert month 14 into month 2 if I don't use date.

Mod ( month - 1 ; 12 ) + 1