Function std.datetime.parseRFC822DateTime

RFC 822 was the original spec (hence the function's name), whereas RFC 5322 is the current spec.

The day of the week is ignored beyond verifying that it's a valid day of the week, as the day of the week can be inferred from the date. It is not checked whether the given day of the week matches the actual day of the week of the given date (though it is technically invalid per the spec if the day of the week doesn't match the actual day of the week of the given date).

If the time zone is "-0000" (or considered to be equivalent to "-0000" by section 4.3 of the spec), a SimpleTimeZone with a utc offset of 0 is used rather than UTC, whereas "+0000" uses UTC.

Note that because SysTime does not currently support having a second value of 60 (as is sometimes done for leap seconds), if the date-time value does have a value of 60 for the seconds, it is treated as 59.

The one area in which this function violates RFC 5322 is that it accepts "\n" in folding whitespace in the place of "\r\n", because the HTTP spec requires it.

Prototypes

SysTime parseRFC822DateTime()(
  char[] value
) @safe;

SysTime parseRFC822DateTime(R)(
  R value
) @safe
if (isRandomAccessRange!R && hasSlicing!R && hasLength!R && (is(Unqual!(ElementType!R) == char) || is(Unqual!(ElementType!R) == ubyte)));

Throws

DateTimeException if the given string doesn't follow the grammar for a date-time field or if the resulting SysTime is invalid.

Example

auto tz = new immutable SimpleTimeZone(hours(-8));
assert(parseRFC822DateTime("Sat, 6 Jan 1990 12:14:19 -0800") ==
       SysTime(DateTime(1990, 1, 6, 12, 14, 19), tz));

assert(parseRFC822DateTime("9 Jul 2002 13:11 +0000") ==
       SysTime(DateTime(2002, 7, 9, 13, 11, 0), UTC()));

auto badStr = "29 Feb 2001 12:17:16 +0200";
assertThrown!DateTimeException(parseRFC822DateTime(badStr));