Hi @alon123!
This sounds like it’s an issue with formatting when the data is passed from the webhook to Google Sheets; the form sends a date and Google Sheets isn’t recognizing it as a date and converts it to a number.
You can check this by looking at the data in and data out for the step in your Zap history. To do that, go to the Zap history for the Zap and click on a Zap run where you know the number was wrong. Go to the Google sheets step and look at the Data in and Data out tabs, data in shows how the information was given to Google Sheets and Data out shows what Google Sheets put into the sheet.
To fix this, the first thing to check is whether the column in Google Sheets is formatted to a date format. If it is, then it’s likely that the issue is what is being passed to the sheet. To change the format of the date being passed to the Sheet, you can add a Formatter by Zapier step in your Zap to change the date format. The Sheet should then recognize the information as a date and not a number. You can learn more about using the Formatter to change date and time formats in this help guide: Modify date and time formats in Zaps.