How to Extract Free Time Slots from Google Calendar in Bulk Using GAS

Introduction

If you use Google Calendar for daily schedule management, do you find yourself manually checking the calendar every time you need to identify or share your available time slots?

This article introduces a tool that uses Google Apps Script (GAS) to extract free time slots from Google Calendar in bulk and display them in Google Sheets.

SANANE

A free downloadable spreadsheet link is provided, so you can start using it right away.

Key Features

Bulk extraction of free time from Google Calendar

This tool extracts free time slots for the next 30 days from Google Calendar and displays them as a list in Google Sheets.

SANANE

This eliminates the need to manually check your schedule and lets you efficiently identify your available time.

Support for multiple calendars

This tool can handle multiple Google Calendars at once.

It retrieves event data from multiple calendars and calculates free time without overlaps, making team scheduling seamless.

Benefits

Save time

No more manually checking for free time — you can significantly reduce the time spent on scheduling. This is especially useful when you need to check multiple calendars.

Easy setup

Setting up the tool is very simple — just configure the initial settings in Google Sheets, enter your Calendar ID, and set the time range.

You can get started immediately without any specialized technical knowledge.

Free to use

This tool is provided for free. Google Sheets and GAS, which power the tool, are also free to use. Anyone can start using it easily.

You can improve your scheduling efficiency without any paid software or services.

How to Use

Copy the Google Spreadsheet

First, access the Google Spreadsheet using the link below:

Google Docs

【公開用】Googleカレンダー空き時間抽出ツール

https://docs.google.com/spreadsheets/d/1rc1wgz-4DWAui3Jtk1QsqlaXSydnqQse649oHrkhQGs/edit?usp=sharing

The linked spreadsheet is view-only, so copy it to make it editable:

1. Click “File” in the top menu bar.
2. Click “Make a copy”.
3. Change the file name to your preferred name and click “Make a copy”.

All subsequent steps should be performed on the copied spreadsheet.

Enter the Calendar ID

Next, select the target Google Calendar.

Enter the Calendar ID in cell B5.

For instructions on how to find your Calendar ID, refer to the following article:

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You can also specify multiple calendars. In that case, separate the Calendar IDs with commas (,).

When specifying multiple Calendar IDs, you must have access permissions for each calendar.

Specifying a Calendar ID for someone else’s calendar that you don’t have access to will not work.

Set working hours

Next, select the start time and end time for your available hours range.

1. Click cell B9 and select the start time.
2. Click cell B10 and select the end time.

The setup is now complete.

Extract free time slots

Click “Custom Menu” in the top menu bar of the spreadsheet.

Click “Extract Free Time”.

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If this is your first time running the script, GAS authorization is required. Refer to the article above for the authorization steps.

After a short wait, a dialog will appear and free time slots for the next 30 days will be displayed starting from cell B15.

If the results don’t appear, click “Custom Menu” > “Extract Free Time” again from the top menu bar.