Fig. 2

Twitter activity behavioral curves B (t). a Normalized count of tweets posted from a location within the United States between 12 p.m. Sunday and 12 p.m. Monday before (red) and the week of (blue) the 2013 Spring Forward Event. The time recorded for the tweet is that local to the author. Though the pattern of behavior is preserved following Daylight Savings, peak activity is translated forward in time. b The same plot, with location of tweet origin restricted to the state of California. California is the state for which we have the most data, and therefore the most representative behavior profile after smoothing with Gaussian Process Regression (lines). We note that Fig. 5 shows behavioral curves for all states. c The smoothed behavioral pattern for California during the hours of 9 p.m. to 3 a.m. Pacific Time. Activity peaks are denoted by vertical dashed lines, and twinflection points are marked by squares. To estimate the behavioral shift in time, we compute the distance along the temporal axis between these pairs of lines/points. California’s BSF peak is 1 h earlier than the SF peak