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| DWORD WINAPI GetNetworkTime( |
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LPCTSTR lpszRemoteHost, |
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UINT nRemotePort, |
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UINT nTimeout |
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The GetNetworkTime function returns the network time from
the specified host. The network time is a 32-bit number, represented
as the number of seconds since midnight, 1 January 1900 UTC.
Parameters
- lpszRemoteHost
- A pointer to the name of the server. The host must be
running a time server that complies with the specifications
outlined in RFC 868.
- nRemotePort
- The port the time server is running on. A value of zero
indicates that the default port number for the service should be
used.
- nTimeout
- The number of seconds that the function will wait for a
response from the server.
Return Value
If the function succeeds, it returns the number of seconds since
midnight, 1 January 1900 UTC. If the function was unable to obtain
the time from the specified host, it returns zero.
Remarks
The GetNetworkTime function will cause the calling thread
to block until the time is returned by the server, or the operation
times out. For applications which require asynchronous operation, the
QueryNetworkTime function should be used instead.
The network time value can represent a date and time up to the
year 2036. It is important to note that the network time value is not
the same as the UNIX time value that is used the standard C library
time functions.
In the United States, the National Institute of Standards and
Technology (NIST) hosts a number of public servers which can be used
to obtain the current time. The following table lists the current
host names and addresses:
| Server Name |
IP Address |
Location |
| time-a.nist.gov |
129.6.15.28 |
Gaithersburg, Maryland |
| time-b.nist.gov |
129.6.15.29 |
Gaithersburg, Maryland |
| time-nw.nist.gov |
131.107.13.100 |
Redmond, Washington |
| time-a.timefreq.bldrdoc.gov |
132.163.4.101 |
Boulder, Colorado |
| time-b.timefreq.bldrdoc.gov |
132.163.4.102 |
Boulder, Colorado |
| time-c.timefreq.bldrdoc.gov |
132.163.4.103 |
Boulder, Colorado |
Time servers are also commonly maintained by Internet service
providers and universities. If you are unable to obtain the time from
a server, contact the system administrator to determine if they have
the standard time service available on port 37.
Requirements
Minimum Desktop Platform: Windows 7 (Service Pack 1)
Minimum Server Platform: Windows Server 2008 R2 (Service Pack 1)
Header File: cstools10.h
Import Library: cstimv10.lib
Unicode: Implemented as Unicode and ANSI versions.
See Also
ConvertNetworkTime,
QueryNetworkTime,
ReadNetworkTime,
TimeInitialize
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