countdown from a date

[bterning]

I am not familiar with Excel jargon, so I'm having a hard time knowing how to ask what I need my spreadsheet today.  This is what I need it to do: When someone admits to the facility I work at, some have 100 days of Medicare to use.  I want their admission date to = 100.  Then whatever the current days is, I would like the days left to subtract from the admission date.  So if I admit on 10/1 and have 100 days, then today is 10/3, that would mean I have 98 days left.  How do I make this happen?

[#2]

@bterning 

Excel treats dates as integers, so you can just subtract them. Assuming admit date, 10/1/20, is in A2, then

Today()-A2  

would give you 2 days (if today were 10/3/20). But, since Medicare counts the day of admission and not the day of discharge, then I would think you would also want to test if Today=Admit Date:

=100-(TODAY()-A2+(TODAY()=A2))

[#3]

@JMB17 

Thank you so much!  It worked!  I want to learn more of this to make my work more efficient.  This is a game changer!

[#4]

Since you are fairly new, I should point out that this part:

(TODAY()=A2)

Works the same as this:
IF(TODAY()=A2,1,0)

For Excel TRUE=1 and FALSE=0, so I'm using a small shortcut.