[SalesForce] Formula field gets populated with respect to other fields

As others have pointed out, the compile size for a given formula includes the compile sizes for other formulas that it has referenced. The additive nature of compile size is causing you to exceed the limit with this one.

Without seeing the content in your other formulas, it's hard to say exactly what's causing the large compile size. Before you leap to Apex, it's worth a look to see if your formulas are written as efficiently as possible (which is a good practice anyway). There is a doc from Salesforce on this very topic, Tips for Reducing Formula Size, which has a number of suggestions and examples:

1. Minimize the number of references to other fields
2. Minimize the number of times formula functions are called
3. Rethink your picklist
4. Think about the problem another way
5. If all else fails, use a workflow field update (or trigger)

Your biggest win will be reducing formulas that are referenced multiple times.

If you did this in workflow with a field update, the formula is unlimited in size. The main drawback to this approach is that the data only updates when the item is updated while formula fields 'update' when they are accessed.

Set the workflow to always fire. let it take all of the data and calculate a response and update a standard field. (resultA)

Then use the formula field to compare that result (resultA) with the items that change as the day changes. (for example: 'days between A and Z < 14' etc)

This way you can have a single call in the formula to a standard field.