Joda

Java Subtract two joda datetimes
https://pupli.net/2016/03/05/java-subtract-two-joda-datetimes/

Java Compare DateTime objects in Joda
https://pupli.net/2016/03/05/java-compare-datetime-objects-in-joda/

Converting a formatted date string to a DateTime object using Joda Time library
https://pupli.net/2019/08/17/converting-a-formatted-date-string-to-a-datetime-object-using-joda-time-library/

Convert Joda-Time `DateTime` with timezone
https://pupli.net/2019/08/17/convert-joda-time-datetime-with-timezone/