Date plus Duration Error in GANTT

Hi - I’m having some difficulty getting a dependency to work. In the first screen shot below you’ll see that row 10 returns a Start date correctly in the start column based on being dependent on row 9:


However, if I then add a duration of 5 days to my Start date, I get a number instead of a date in the formulae details:


This doesn’t then allow my GANTT (based on start date and duration) to work correctly, but it also suggests its a Start Date Error:

Any help much appreciated!

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Hi there
try to set your duration column as duration not as number, maybe it helps.

I’ve seen this happen somewhat randomly when I use formulas to generate dates (like you do with your Start Date).

I had this doc I couldn’t get a simple thisRow.Date+7 to work yesterday, it always returned a 43xxx number… ended up having to use Date(Year(thisRow.Date+7),Month(thisRow.Date+7) ,Day(thisRow.Date+7) ). Just went back to it now and tried thisRow.Date+7 again and this time it’s working. :thinking:

Thanks both @Tomas_Sebes & @Dalmo_Mendonca - Both these suggestions didn’t work straight up, but when I applied your suggestion @Dalmo_Mendonca to the calculations in my Start column (where I use the IF statement to bring in the dependency end date) it works. The amended formula is now as follows:


I’m not quite sure about the Error Message Wrong argument type though, but it doesn’t seem to make any difference to the calculation.

My next challenge is to see how to handle multiple dependencies for a row (and choose the later date)!

Thanks again!

The warning might be because you have column formulas referencing each other, so it seems Coda can’t figure out column End's type because of a possible circular reference. You can try filtering out the current task/row from the Dependent On select list, but that might not be enough.

In most cases, you can ignore this warning if you’re getting the correct results.

To get the later date you may try something like thisRow.[Dependent On].End.Sort().Last()

Thanks @Dalmo_Mendonca - works perfectly!