HS NTP is a software library in C (supplied with full source code) which implements the client side of Network Time Protocol (NTP) over UDP socket layer according to RFC1769 and RFC1305. HS NTP Library allows a user application to synchronise local system time to remote NTP server time. First user application calls HS NTP initialisation function supplying pointers to callback functions in user code for timer management and for reporting NTP events to user. To obtain time difference between local system and remote NTP server, the user application calls HsNtpGetTime function, specifying NTP server name or IP address and source UDP port to use. HS NTP library then resolves the server name, formats and sends NTP time request packet according to RFC1305 and RFC1769 standard. Once HS NTP has received NTP time reply from NTP server it analyses the reply and reports the resulting time difference to user application via callback function.