A string when not using an output range; void otherwise.
assert(Date.init.toSimpleString == "null"); assert(Date(2010, 7, 4).toSimpleString == "2010-Jul-04"); assert(Date(1998, 12, 25).toSimpleString == "1998-Dec-25"); assert(Date(0, 1, 5).toSimpleString == "0000-Jan-05"); assert(Date(-4, 1, 5).toSimpleString == "-0004-Jan-05");
Converts this Date to a string with the format YYYY-Mon-DD. If writer is set, the resulting string will be written directly to it.