Not in the the apllication, on your actual device if your on a chromebook(any chromebook with a latest update) should have night mode, if your on IOS, heres the information on night mode for that, its different from dark mode though; Night Shift is available on iPhone 5s or later, iPad Pro, iPad (5th generation and later), iPad Air or later, iPad mini 2 or later, and iPod touch (6th generation and later). Some display accessibility settings, including Invert Colors, Grayscale, and Increase Contrast, might turn off Night Shift or True Tone display.