The accuracy of Advanced Time Synchronizer depends on the accuracy of the selected time protocol and network delays:

• The most accurate SNTP protocol is 200-picoseconds accurate and takes network delays. The actual accuracy of this protocol is about 1/10 of a second, and the faster your Internet connection is the higher is its accuracy.
• The accuracy of the DAYTIME protocol depends on the syntax of the string the time on the server is presented in. Most servers are 1-second accurate, but the protocol standard does not define any definite accuracy, thus, the sent string can contain additional data making it possible to improve the accuracy. Servers using the syntax of the string proposed by NIST send such data. Such servers have better than 1-second accuracy.
• The Time protocol is about 1-second accurate and does not provide any opportunities to improve its accuracy.