curl_getdate - Convert a date string to number of seconds
#include <curl/curl.h>
time_t curl_getdate(char *datestring, time_t *now);
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.
This function works with valid dates and does not always detect and reject wrong
dates, such as February 30.
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.
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);
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.
Always
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.)
curl_easy_escape(3),
curl_easy_unescape(3),
CURLOPT_TIMECONDITION(3),
CURLOPT_TIMEVALUE(3)