cal - The Console Calendar Generator

I had need of a simple program that could display a calendar when I'm working on the command line. This small program fits my needs and I'm hopeful it may be useful to others.

Command Line Options

Parameters

Parameters are the arguments provided to the program. They do not include the options above.

Execution

This is a java program that is all bundled into a single jar file. To run a jar file on the command line, simply type:

java -jar cal.jar

Please note that cal.jar must be in your path.

Examples

Command|Result
---|---|
java -jar cal.jar | Display the current year
java -jar cal.jar -n 4 | Display the current year - 4 months per row
java -jar cal.jar 9 | Display September of the current year
java -jar cal.jar 2022 | Display the entire year 2022
java -jar cal.jar 9 2022 | Display September of 2022
java -jar cal.jar -D 6 | Display June of current year in debug mode
java -jar cal.jar -h | Show this help information

References

I was able to use several web pages for sources of formulas for the program. These were very helpful and I'd like to thank their authors for taking the time to record them publicly.

Determine how to calculate the first day of a month given the month and year:

• https://www.tondering.dk/claus/cal/chrweek.php#calcdow
• http://www.cplusplus.com/forum/general/174165/

Calculate if the year provided is a leap year:

• https://www.wikihow.com/Calculate-Leap-Years