DateCalc
DateCalc is a small stand-alone Java program that provides simple command-line date expression calculations such as
today yesterday month(-1).end date(2006-12-20).month.name
| Java | Java 5+ (JRE 1.5) |
Unpack the distribution ZIP to a directory of choice. Only the JAR file is needed for the execution, all dependent libraries are included.
The JAR file is an executable JAR file that can be run with the -jar option of the JVM. The command below will print the date of today.
yes> java -jar datecalc-2.0.jar 2008-02-18 13:08:02
The CLI accepts command-line options as well. Use options --help to show the available options.
yes> java -jar target\datecalc-2.0.jar --help usage: java -jar datecalc-2.0.jar [options] expr-1 expr-2 ... DateCalc - version 2.0 -f,--format <pattern> Sets the default format. -h,--help Prints the help info -l,--locale <lang/country-code> Sets the default locale. -z,--timezone <timezone-id/offset> Sets the default timezone. Example: java -jar datecalc-2.0.jar --locale=it --timezone=PST today.day.end month(-1).day.start.iso
The default settings for the date-time properties are taken from the platform defaults. Usage of one or more of these options affect the root date-time object. For example, setting the locale to another language than the default, changes the string names of month and week-days.
Add one or more date expression(s) (see Reference Page ) as arguments to the program and each will be evaluted and printed one at each line.
yes> java -jar datecalc-2.0.jar today yesterday.day.end today.day(12) "today.format(d MMMM yyyy)" date(2006-10-03).day.end month(-1).month.end.day.start today.month.name tomorrow.day.name 2008-02-18 13:38:40 2008-02-17 23:59:59 2008-03-01 13:38:40 18 februari 2008 2006-10-03 23:59:59 2008-01-31 00:00:00 februari tisdag
DateCalc can be used as an ordinary Java library as well. There are two usage approaches: expressions or methods.
The CLI reads expressions from the command line and feeds them into the parser. The parser can be used programmatically. It should be initialized with a date-time object and can then parse expressions. the returned value is of multi-type and is therefor represented by a a ParseResult object, that contains one single value; either a date-time or an element, or a string or an integer.
DateTime root = DateTimeImpl.create();
Parser parser = new ParserImpl(root);
ParseResult result = parser.parse("date(2006-10-03).day.end");
DateTime date = result.getDateTime();
It is also possible to use its methods directly.
DateTime date = DateTimeImpl.create("2006-10-03").getDay().getEnd();
See the JavaDocs for a complete listing of the API.