Time zone
Copenhagen (as the rest of Denmark) is one hour ahead of Greenwich Mean Time (GMT), i.e. GMT +1. Summer time changes as with the rest of Europe (late March to late October).
The northern location of Denmark means that summer nights are short and light (in June, the sun sets at approx. 10 pm and rises at approx. 4.30 am), while winter nights are correspondingly long and dark (in December, the sun sets at approx. 3.40 pm and rises at approx. 8.40 am).
Weather
Copenhagen enjoys a mild climate. July is normally the warmest month with an average temperature of just below 20°C (68°F). February is generally the coldest with an average of just below 0°C (32°F). Snowfalls are normal during winter, but because of the mild climate the ground will far from be covered by snow the entire winter.
The weather can, however, be quite unpredictable so be sure to bring warm clothes even during summer if you plan to spend time outside.
The Copenhagen weather right now