Apple has pushed watchOS 2.1 to Apple Watch owners and is now available to download via the Watch app on your iPhone.
watchOS 2.1 includes a variety of bug fixes to improve the performance as well as support for several new languages including Arabic, Czech, Greek, Hebrew, Hungarian, Malay, Portuguese, and Vietnamese, along with expanded dictation and Siri support for several languages. Bug fixes includes fixes for Calendar, Power Reserve mode, third-party apps, and more.
To grab the update, simply go to the Watch app on your iPhone and then go to General > Software Update. Your Apple Watch must have at least 50% battery, and it must be connected to your Apple Watch charger, as well as within range of your iPhone.