To mark the start of daylight saving time today, we venture off to Olomouc, a city in the Czech Republic. In the city’s Upper Square, next to the tower of the 15th-century Town Hall, is Olomouc’s famous astronomical clock. The clock doesn’t just keep the time of day, but tracks the phases of the moon, days of the year, and even has a star map to indicate what might be visible in the night sky. In this photo, you can see the buildings of the square reflected in the clock’s face.