Dusk2Dawn is a plugin for the popular 'EEGLAB' MATLAB toolbox, which allows you to easily clean whole-night sleep EEG using Artifact Subspace Reconstruction (ASR). As ASR must be calibrated using relatively clean reference data, and there is considerable variability in signal-to-noise ratio across and within sleep-stages, a standard ASR applied to the whole-night would lack sensitivity during lower-amplitude N1 and REM stages, while inappropriately removing large-amplitude brain signals such as slow-waves in N2 and N3 stages. Dusk2Dawn therefore implements two methods to solve this problem: (1) Running ASR separately for each sleep stage, (2) Running ASR in a short sliding-window (e.g. 4 - 16 minutes). The other main benefit of Dusk2Dawn is that it allows you to easily and automatically run ASR several times with different sets of parameters (e.g. different levels of ASR severity) and easily test and visualize the effects of each run-through, before choosing which final dataset to use for your analysis.