Cycling in the dark - the impact of Standard Time and Daylight Saving Time on bicycle ridership.

The European Union is in the process of abolishing the bi-annual clock change. Against this backdrop, we analyze how daylight and twilight affect the sustainable transport mode of cycling, and find that better daylight conditions generally lead to higher levels of cycling. The extent of this effect depends on the type of traffic and the time of day. An all-year implementation of Daylight Saving Time would then lead to an increase in overall cycling levels of around 3.14 %-3.37 %, compared to an all-year Standard Time. This would imply an increase of around 1.27-1.36 billion cycled kilometers per year in Germany alone. Additionally, we provide monetary estimates for the external effects of such changes in cycling levels.