Dateutils are a bunch of tools that revolve around fiddling with dates and times in the command line, with a strong focus on use cases that arise when dealing with large amounts of financial data. Their target market is shell scripts that need date calculations or calendar conversions, and as such they are highly pipe-able and modeled after their well-known cousins (e.g. dtest vs. test, or dgrep vs. grep).
JS Date Range Picker is a package to let the user pick a range between two dates. It can be used to present two form inputs that let the user choose dates using calendar pull down menus. The dates may be validated so the range end date is not set to a day before the range start date. The format of the dates and the week start day are configurable parameters. The chosen dates are returned in the ISO-8601 extended format.