How to subtract days, months or years from a date?

Deadlines, reminders and earliest start dates are often some days or months before another date. Counting back by hand is easy to get wrong across months and years, and Google Forms has no option to do it. With Formfacade, you use the SUBTRACT function in the Calculate option of a date question, and your users see the new date as soon as the first date is there.

Create your form and follow the steps below.

Subtract days from a date

  • On the page that opens, name your form, click Build form and click Proceed.
  • Click on the "Edit" tab.
The tabs Edit, Preview, Share and Responses, with Edit marked
  • Click on the + icon (Add field) in the toolbar on the right.
  • Enter "Input date" as the question and select Date in the question type list
  • Click on the + icon again
  • Enter "Subtract 7 days from input date" as the question and select Date in the question type list
The toolbar on the right of the Edit tab, with the + icon marked
Click on the ⚙️ icon at the bottom right of the question.
The form in Formfacade, with the EDIT tab, the Subtract 7 days from input date question and its gear icon marked
Select the "Answer" tab.
The field settings panel with the Answer tab and the Calculate box marked

SUBTRACT function

You can subtract days from a date by specifying "days" as the term in the SUBTRACT function.
Syntax:
subtract(number_of_days, "days")
Example usage:
TODAY().subtract(30,"days")
Inputdate.subtract(7,"days")
Note: To enter Inputdate, type @ in the calculate option and select the Input date question from the list.
Write the formula in the Calculate option as shown below. Click Save.
The Calculate box with the Input date field and .subtract(7,"days")

Subtract months from a date

You can subtract months from a date by specifying "months" as the term in the SUBTRACT function.
Syntax:
subtract(number_of_months, "months")
Example usage:
TODAY().subtract(6,"months")
Inputdate.subtract(2,"months")
Add another date question the same way, click on the ⚙️ icon and write the formula in the Calculate option as shown below. Click Save.
The Calculate box with the Input date field and .subtract(2,"months")

Subtract years from a date

You can subtract years from a date by specifying "years" as the term in the SUBTRACT function.
Syntax:
subtract(number_of_years, "years")
Example usage:
TODAY().subtract(1,"years")
Inputdate.subtract(5,"years")
Add another date question the same way, click on the ⚙️ icon and write the formula in the Calculate option as shown below. Click Save.
The Calculate box with the Input date field and .subtract(5,"years")
As soon as the user enters the input date, the form shows the new dates.
The Date functions form with an input date of 1 November 2026 and the dates 7 days, 2 months and 5 years before it

Summary

If you need a date that is some days, months or years before another date, Google Forms cannot calculate it. With Formfacade, you can use the SUBTRACT function in the Calculate option and the new date will be displayed as soon as the user enters the first date. Create your form and complete the steps above. If you have any questions, write to support.

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