Technical information

Chapter 2: AT+i Commands Reference
May 31, 2008 AT+i Commands Reference Manual 2-61
Network Time Client
W24 incorporates a Simple Network Time Protocol (SNTP) client. With this protocol support,
W24 can be configured to check SNTP servers for current time and date each time it goes online.
W24 is configured to retrieve time data from a Network Time Server each time it goes online with
the NTOD parameter. After updating its internal Time-Of-Day (TOD) registers at least once, W24
continues to keep track of time independently, even after it goes offline.
When W24 contains real TOD data, e-mails sent are automatically stamped with Time and Date
of delivery, according to RFC (822) definition for the date header field. In addition, the AT+iRP8
report returns the current time and date.
W24 also contains parameters to configure local GMT offset and a DSTD (Daylight Savings
Time) rule. These parameters allow W24 to determine the local TOD. When W24 is configured
for TOD retrieval from a Network Time Server, W24 automatically retrieves an updated time
reading every two hours while online. This configuration improves the long-term accuracy of its
internal time management.