How do I create a formula that would allow me to subtract from a d

[Justlearning]

I want to create a seed starting chart in excel, but don't know if I can
create a formula which would allow me to use dates. I want to have a column
where I enter the number of weeks from the first frost free date, and then
have Excel calculate what the seed starting date would be.

 

[JE McGimpsey]

one way:

A1 <last ff date>
A2 # weeks before last ff date to start

A3: =A1-7*A2

format A3 as a date.

 

[Justlearning]

Oh! I get it! Thank you, thank you very much! That was very helpful.

 

[Justlearning]

I am so excited to have this work! Thank you! You cannot even imagine how
excited I am about such a simple formula!

Now I have a problem though: What do I do if the date varies - such as the
# of weeks before the last ff date are 5 to 6 weeks? Will I have to use two
seperate columns?

 

[JE McGimpsey]

If you want to retain the information for each set of seedlings, use
more than one column (or row, if you prefer). You can copy the formula
over or down as appropriate. Since the last ff date won't change, use an
absolute address:

A B C
1 <ff date> Plant 1 Plant 2
2 <wks from ff dt> <wks from ff dt>
3 =$A$1-B2*7 =$A$1-C2*7

then when you copy, the A1 reference will stay the same while the value
you're subtracting will automatically change.

 

[Justlearning]

Thank you, that is very helpful!

If you want to retain the information for each set of seedlings, use
more than one column (or row, if you prefer). You can copy the formula
over or down as appropriate. Since the last ff date won't change, use an
absolute address:

A B C
1 <ff date> Plant 1 Plant 2
2 <wks from ff dt> <wks from ff dt>
3 =$A$1-B2*7 =$A$1-C2*7

then when you copy, the A1 reference will stay the same while the value
you're subtracting will automatically change.