Ubuntu Manpage: curl_getdate - Convert a date string to number of seconds

Provided by: libcurl4-doc_7.81.0-1ubuntu1.20_all

NAME

       curl_getdate - Convert a date string to number of seconds

SYNOPSIS

       #include <curl/curl.h>

       time_t curl_getdate(char *datestring, time_t *now);

DESCRIPTION

       curl_getdate(3)  returns the number of seconds since the Epoch, January 1st 1970 00:00:00 in the UTC time
       zone, for the date and time that the datestring parameter specifies. The now parameter is not used,  pass
       a NULL there.

PARSING DATES AND TIMES

A "date" is a string containing several items separated by whitespace. The order of the items is
immaterial. A date string may contain many flavors of items:

calendar date items
Can be specified several ways. Month names can only be three-letter english abbreviations,
numbers can be zero-prefixed and the year may use 2 or 4 digits. Examples: 06 Nov 1994,
06-Nov-94 and Nov-94 6.

time of the day items
This string specifies the time on a given day. You must specify it with 6 digits with two colons:
HH:MM:SS. To not include the time in a date string, will make the function assume 00:00:00.
Example: 18:19:21.

time zone items
Specifies international time zone. There are a few acronyms supported, but in general you should
instead use the specific relative time compared to UTC. Supported formats include: -1200, MST,
+0100.

day of the week items
Specifies a day of the week. Days of the week may be spelled out in full (using english):
`Sunday', `Monday', etc or they may be abbreviated to their first three letters. This is usually
not info that adds anything.

pure numbers
If a decimal number of the form YYYYMMDD appears, then YYYY is read as the year, MM as the month
number and DD as the day of the month, for the specified calendar date.

EXAMPLE

        time_t t;
        t = curl_getdate("Sun, 06 Nov 1994 08:49:37 GMT", NULL);
        t = curl_getdate("Sunday, 06-Nov-94 08:49:37 GMT", NULL);
        t = curl_getdate("Sun Nov  6 08:49:37 1994", NULL);
        t = curl_getdate("06 Nov 1994 08:49:37 GMT", NULL);
        t = curl_getdate("06-Nov-94 08:49:37 GMT", NULL);
        t = curl_getdate("Nov  6 08:49:37 1994", NULL);
        t = curl_getdate("06 Nov 1994 08:49:37", NULL);
        t = curl_getdate("06-Nov-94 08:49:37", NULL);
        t = curl_getdate("1994 Nov 6 08:49:37", NULL);
        t = curl_getdate("GMT 08:49:37 06-Nov-94 Sunday", NULL);
        t = curl_getdate("94 6 Nov 08:49:37", NULL);
        t = curl_getdate("1994 Nov 6", NULL);
        t = curl_getdate("06-Nov-94", NULL);
        t = curl_getdate("Sun Nov 6 94", NULL);
        t = curl_getdate("1994.Nov.6", NULL);
        t = curl_getdate("Sun/Nov/6/94/GMT", NULL);
        t = curl_getdate("Sun, 06 Nov 1994 08:49:37 CET", NULL);
        t = curl_getdate("06 Nov 1994 08:49:37 EST", NULL);
        t = curl_getdate("Sun, 12 Sep 2004 15:05:58 -0700", NULL);
        t = curl_getdate("Sat, 11 Sep 2004 21:32:11 +0200", NULL);
        t = curl_getdate("20040912 15:05:58 -0700", NULL);
        t = curl_getdate("20040911 +0200", NULL);

STANDARDS

       This  parser handles date formats specified in RFC 822 (including the update in RFC 1123) using time zone
       name or time zone delta and RFC 850 (obsoleted by RFC 1036) and ANSI C's asctime() format. These  formats
       are the only ones RFC 7231 says HTTP applications may use.

AVAILABILITY

       Always

RETURN VALUE

       This  function  returns  -1  when  it  fails to parse the date string. Otherwise it returns the number of
       seconds as described.

       On systems with a signed 32 bit time_t: if the year is larger than 2037 or less than 1903, this  function
       will return -1.

       On  systems  with  an  unsigned  32  bit  time_t: if the year is larger than 2106 or less than 1970, this
       function will return -1.

       On systems with 64 bit time_t: if the year is  less  than  1583,  this  function  will  return  -1.  (The
       Gregorian calendar was first introduced 1582 so no "real" dates in this way of doing dates existed before
       then.)