Microsoft will begin rolling dark mode out to Microsoft 365 this week. You’ll see it first on Office.com for web and mobile and Outlook mobile apps.

Dark mode brings plenty of benefits. Many people just prefer the aesthetics, but you can also expect reduced eye strain and improved battery life. As a result, Microsoft’s adoption of dark mode can have a big impact. Over 180 million monthly active business users and 35 million consumer subscribers use Office 365.

Here is how Jon Friedman, Microsoft’s head of design and research, explains it:

Our tools are used to keep up to speed on everything from work communication to personal events that include friends and family to changes in shared documents. This often means viewing email, calendars, or files in places where the default white mode may be less suitable, like darkened airplanes, movie theaters, or in bed at night.

Our design research specifically focused on these contexts where folks would want to use dark mode, and the response was very positive. While some Dark Mode experiences can be neon or overly bright, people felt that Outlook mobile kept the kind of relaxed feeling you might want in a dimly lit living room or bedroom. They described the experience as comfortable, crisp, clear, and aesthetically pleasing, a nod to how dark mode can reduce eye strain.

The core Office apps (Word, Excel, PowerPoint, SharePoint, OneDrive, Planner, and To-Do) will get dark mode following the launches of Android 10 and iOS 13 this fall. At that point, Outlook will automatically switch to dark mode based on your preferences. In the meantime, Outlook for Android will automatically switch to dark mode when you choose Power Saver. Next up on Microsoft’s dark mode list: Planner and OneDrive on the web.