Download Day One

Name: Day One
Author: Day One

By: Day One

Download Day One (current and past versions) for Firefox

Latest Version: 1.3.5 Updated: 7 months ago

Ready to install?

Day One is available to install from Firefox Add-ons Store and for download from this page.

View source code

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Total downloads

Available versions

You can find the current and older versions of Day One here. You can download the archived versions or inspect their source codes.

As a free user, you can download up to 3 latest versions.

Upgrade to download older versions

Version	Download	Size	Timestamp
1.3.5	XPI · ZIP · Source code	888.32KB	2025-11-18
1.3.3	XPI · ZIP · Source code	844.09KB	2025-09-26
1.3.0	XPI · ZIP · Source code	840.94KB	2025-09-11
1.2.0	Paid users only	837.15KB	2025-08-29
1.1.0	Paid users only	834.39KB	2025-08-19

2025-11-18 · 0 downloads

XPI ZIP Source code

2025-09-26 · 0 downloads

XPI ZIP Source code

2025-09-11 · 0 downloads

XPI ZIP Source code

2025-08-29 · 0 downloads

Paid users only

2025-08-19 · 0 downloads

Paid users only

Install XPI file

An XPI file, short for "XPInstall," is a compressed file format used primarily by Mozilla applications, like Firefox and Thunderbird, to distribute and install add-ons or extensions. These files are similar in function to CRX files for Chrome but cater to the Mozilla ecosystem.

Simply drag-and-drop the XPI into Firefox to install the add-on.

Install ZIP file

Download the Day One ZIP file.
In Firefox browser, go to about:addons to open Add-ons Manager
Click on ⚙, Install Add-on From File
Select the Day One ZIP file from step 1. Day One is now installed on your browser.