# Date based invoicing

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I am trying to design a rental system with automatic invoicing based on the date such that:

if the rental start date is in the current month and the start date is not the 1st of the month then

Rental/Number of days in the month*(number of days in the month-Rental start date)+commision.

And conversely if the rental end date is in the current month etc.

Can anyone help construct this formula please

Chris

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Case (Month(rentalStartDate)=Month(Status(CurrentDate)and Day(rentalStartDate) > 1 ; (rentalAmount/numberDaysinMonth)*(Date(Month(Status(CurrentDate)))+1,0,Year(Status(CurrentDate)))-rentalStartDate)+commission

The other calculations would be similar. In version 7, using Let, we could simplify the calculation drastically.

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Thank you for your help, I have today received my FMP7 (V7.02) and installed it, how would Let be simpler. By the way FMP7 appears much slower launching a solution than either 5.5 or 6. Is this because these solutions were designed in previous versions and then converted.

Chris

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I can not get this expression to work, numberDaysinMonth, I have tried different syntax but to no avail

Chris

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It's hard to know what the last day of the month is. But it's easy to know what the first day of next month is, then substract 1:

Day ( Date ( Month ( Get (CurrentDate) ) + 1; 1; Year ( Get (CurrentDate)) ) - 1 )

Actually, there is a special, rather odd way to get the last day of the month. It's day 0 of next month. So this also works:

Day ( Date ( Month ( Get (CurrentDate) ) + 1 ; 0; Year ( Get (CurrentDate)) ) )

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Fenton:

Nicely done. It's always good to see some code that gets the cereal into the bowl in just the right (non-rectilinear) way.

-Stanley

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Wow, now I know why I feel dumb, it's because I am. Thanks for all your help

Chris

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