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

Provided by: libcurl4-doc_7.58.0-2ubuntu3.24_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.

EXAMPLES

       Sun, 06 Nov 1994 08:49:37 GMT
       Sunday, 06-Nov-94 08:49:37 GMT
       Sun Nov  6 08:49:37 1994
       06 Nov 1994 08:49:37 GMT
       06-Nov-94 08:49:37 GMT
       Nov  6 08:49:37 1994
       06 Nov 1994 08:49:37
       06-Nov-94 08:49:37
       1994 Nov 6 08:49:37
       GMT 08:49:37 06-Nov-94 Sunday
       94 6 Nov 08:49:37
       1994 Nov 6
       06-Nov-94
       Sun Nov 6 94
       1994.Nov.6
       Sun/Nov/6/94/GMT
       Sun, 06 Nov 1994 08:49:37 CET
       06 Nov 1994 08:49:37 EST
       Sun, 12 Sep 2004 15:05:58 -0700
       Sat, 11 Sep 2004 21:32:11 +0200
       20040912 15:05:58 -0700
       20040911 +0200

STANDARDS

       This parser was written to handle 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.

RETURN VALUE

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

       If the year is larger than 2037 on systems with 32 bit time_t, this function  will  return
       0x7fffffff (since that is the largest possible signed 32 bit number).

       Having a 64 bit time_t is not a guarantee that dates beyond 03:14:07 UTC, January 19, 2038
       will work  fine.  On  systems  with  a  64  bit  time_t  but  with  a  crippled  mktime(),
       curl_getdate(3) will return -1 in this case.