Objective-C

Get Current Date/Time from NIST Time Server

See more Socket/SSL/TLS Examples

Demonstrates using Chilkat Socket to connect to an NIST time server and (using the old Time Protocol (RFC 868)), will read the current GMT time.

Note: This is not necessarily the very best means for getting the current date/time. The most commonly used time protocol is the Network Time Protocol (RFC-1305).

Objective-C

#import <CkoSocket.h>
#import <CkoDateTime.h>

BOOL success = NO;

//  This example requires the Chilkat API to have been previously unlocked.
//  See Global Unlock Sample for sample code.

CkoSocket *socket = [[CkoSocket alloc] init];

//  Connect to an NIST time server and read the current date/time
int maxWaitMs = 4000;
BOOL useTls = NO;
success = [socket Connect: @"time-c.nist.gov" port: [NSNumber numberWithInt: 37] ssl: useTls maxWaitMs: [NSNumber numberWithInt: maxWaitMs]];
if (success != YES) {
    NSLog(@"%@",socket.LastErrorText);
    return;
}

//  The time server will send a big-endian 32-bit integer representing
//  the number of seconds since since 00:00 (midnight) 1 January 1900 GMT.
//  The ReceiveInt32 method will receive a 4-byte integer, but returns
//  true or false to indicate success.  If successful, the integer
//  is obtained via the ReceivedInt property.
BOOL bigEndian = YES;
success = [socket ReceiveInt32: bigEndian];
if (success != YES) {
    NSLog(@"%@",socket.LastErrorText);
    return;
}

CkoDateTime *dt = [[CkoDateTime alloc] init];
[dt SetFromNtpTime: socket.ReceivedInt];

//  Show the current local date/time
BOOL bLocalTime = YES;
NSLog(@"%@%@",@"Current local date/time: ",[dt GetAsRfc822: bLocalTime]);

maxWaitMs = 10;
[socket Close: [NSNumber numberWithInt: maxWaitMs]];