The Central Office of Measures (GUM) presents the official application displaying the current official time in Poland, collected from time servers located in the Time and Frequency Laboratory of GUM. Servers are connected to the state master of time and frequency measures. With this application: you will display on your device, a full-screen clock with the official time valid in the area of ​​Poland; - you will learn the advantages and disadvantages of regular time changes (summer / winter) or stays with one time all year round - you will learn how atomic clocks work and what is the transfer of time; - you will find out when you celebrated your birthday living on eg Mars - you will learn the largest knowledge base on time.