The date time of your PC (specific for windows) sync with one of the listed NTP server. This time sync happens every 7 days and with by default. You can also manually sync or update your time. To do that: Click on your system time > "Change date time settings" > "Internet Time" tab > "Change settings and click on Update now to sync. You can also resync time from command prompt by using command line utility called w32tm: cmd> w32tm /resync The default time to automatically sync time with any NTP server is 604800 seconds which is 7 days if you convert. You can change this settings by making edits to REGISTRY using regedit. Warning: Always backup your current registry state before making any changes. The key to change the auto time sync - time interval settings is located at: » Read more