Calculating Days b/n Dates based on If/Then|Power Pivot|Excel Forum|My Online Training Hub

First I tried to make a measure, and that didn't work, and then I tried a calculated column, and that didn't work either b/c I am mixing text and dates.

In a table named "Log," I have three columns called Log[EggStart], Log[LarveStart], and Log[PupaStart]. Each has a date when they start their particular stage--this table is updated daily. So on any given day, not all columns may have a date.

Example:

Specimen      EggStart        LarveStart      PupaStart

0256            12/31/2023     2/4/2024      5/3/2024

1405               3/4/2024     4/1/2024

0382               5/1/2024

My calculated column in the PowerPivot section has a column called "Stage," which calculates the current stage based on the above dates (and what is blank.)

Now, I want to calculate the current stage days. So if Log[Stage]="Egg", then today()-Egg[Start]. However, this totally isn't working. Can you help?