Ctime format usage

You can use the ctime class to conveniently obtain the current system time and convert it to various formats.

TheFormatArgument consists of one or more codes; as inPrintf, The formatting codes are preceded by a percent sign (%). Characters that do not begin%Are copied unchangedStrdest.TheLc_timeCategory of the current locale affects the output formattingStrftime. (For more information onLc_time, See setlocale.) The formatting codesStrftimeAre listed below:

%

Abbreviated weekday name

%

Full weekday name

% B

Abbreviated month name

% B

Full month name

% C

Date and Time Representation appropriate for locale

% D

Day of month as decimal number (01-31)

% H

Hour in 24-hour format (00-23)

% I

Hour in 12-hour format (01-12)

% J

Day of year as decimal number (001-366)

% M

Month as decimal number (01-12)

% M

Minute as decimal number (00-59)

% P

Current locale's a. m./P. M. Indicator for 12-hour clock

% S

Second as decimal number (00-59)

% U

Week of year as decimal number, with Sunday as first day of week (00-53)

% W

Weekday as decimal number (0-6; Sunday is 0)

% W

Week of year as decimal number, with Monday as first day of week (00-53)

% X

Date representation for current locale

% X

Time Representation for current locale

% Y

Year without Century, as decimal number (00-99)

% Y

Year with Century, as decimal number

% Z, % Z

Either the time-zone name or time zone abbreviation, depending on registry settings; no characters if time zone is unknown

%

Percent sign

As inPrintfFunction,#Flag may prefix any formatting code. In that case, the meaning of the format code is changed as follows.

Format code	Meaning
% #,% #,% # B,% # B,% # P,% # X,% # Z,% # Z,% # %	#Flag is ignored.
% # C	Long Date and Time Representation, appropriate for current locale. For example: "Tuesday, March 14,199 5, 12:41:29 ".
% # X	Long date representation, appropriate to current locale. For example: "Tuesday, March 14,199 5 ".
% # D,% # H,% # I,% # J,% # M,% # M,% # S,% # U,% # W,% # W,% # Y,% # Y	Remove leading zeros (if any ).

Requirements

Routine	Required Header	Compatibility
Strftime	<Time. h>	ANSI, WIN 98, win me, Win NT, Win 2000, Win XP
Wcsftime	<Time. h> or <wchar. h>	ANSI, WIN 98, win me, Win NT, Win 2000, Win XP

 

Example

// Crt_times.c/* This program demonstrates these time and date functions: * _ time64 _ ftime64 _ ctime64 asctime * _ localtime64 _ gmtime64 _ mktime64 _ tzset * _ strtime _ strdate strftime ** also the global variable: * _ tzname */# include <time. h> # include <stdio. h> # include <sys/types. h> # include <sys/timeb. h> # include <string. h> int main () {char tmpbuf [128], ampm [] = "am"; _ time64_t ltime; struct _ timeb64 Tstruct; struct TM * today, * GMT, Xmas = {0, 0, 12, 25, 11, 93};/* Set Time Zone from TZ environment variable. if tz Is not set, * the operating system is queried to obtain the default value * for the variable. */_ tzset ();/* display Operating System-style date and time. */_ strtime (tmpbuf); printf ("OS time: \ t % s \ n", tmpbuf); _ strdate (tmpbuf ); printf ("OS Date: \ t % s \ n", tmpbuf) ;/* Get Unix-style time and display as number and string. */_ time64 (& ltime); printf ("time in seconds since UTC 1/1/70: \ t % LD \ n", ltime); printf ("UNIX time and date: \ t % s ", _ ctime64 (& ltime);/* display UTC. */GMT = _ gmtime64 (& ltime); printf ("Coordinated Universal Time: \ t % s", asctime (GMT )); /* convert to Time Structure and adjust for PM if necessary. */today = _ localtime64 (& L Time); If (today-> tm_hour> = 12) {strcpy (ampm, "PM"); today-> tm_hour-= 12 ;} if (today-> tm_hour = 0)/* adjust if midnight hour. */today-> tm_hour = 12;/* Note how pointer addition is used to skip the first 11 * characters and printf is used to trim off terminating * characters. */printf ("12-hour time: \ t %. 8 S % s \ n ", asctime (today) + 11, ampm);/* print additional time informatio N. */_ ftime64 (& tstruct); printf ("plus milliseconds: \ t % u \ n", tstruct. millitm); printf ("zone difference in hours from UTC: \ t % u \ n", tstruct. timezone/60); printf ("Time Zone name: \ t % s \ n", _ tzname [0]); printf ("Daylight Savings: \ t % s \ n ", tstruct. dstflag? "Yes": "no");/* Make time for noon on Christmas, 1993. */If (_ mktime64 (& Xmas )! = (_ Time64_t)-1) printf ("Christmas \ t % s \ n", asctime (& Xmas )); /* use time structure to build a customized time string. */today = _ localtime64 (& ltime);/* use strftime to build a customized time string. */strftime (tmpbuf, 128, "Today is % A, day % d of % B in the year % Y. \ n ", today); printf (tmpbuf );}

Sample output

 
OS time: 14: 15: 49os Date: 02/07/02 time in seconds since UTC 1/1/70: 1013120149 UNIX time and date: Thu Feb 07 14:15:49 2002 Coordinated Universal Time: thu Feb 07 22:15:49 200212-hour time: 02:15:49 pmplus milliseconds: 455 zone difference in hours from UTC: 8 Time Zone name: Pacific Standard timedaylight savings: nochristmas sat Dec 25 12:00:00 1993
 

The following is a simple example:

Cstring msg1 = "aaaaaaaaaaa ";



Killtimer (1 );

 

Ctime T = ctime: getcurrenttime ();

Char sztime [8];

Int nhour = T. gethour ();

Int nminute = T. getminute ();

Int nsecond = T. getsecond ();

Wsprintf (sztime, "% 02i: % 02i: % 02i", nhour, nminute, nsecond); // two tables are generally used in minutes.

M_edit1 = sztime;

Updatedata (false );

Settimer (1, 1000, null );

Msg1 = T. Format ("% d-% m-% Y"); // you can see the format function.

MessageBox (msg1 );

For the parameter meanings in format, see the preceding description.