Date Utilities

A collection of date utility functions for JavaScript. These functions provide additional date manipulations not available in the default JavaScript Date object.

Features

• Get the first day of the week (Monday)
• Get the last day of the week (Sunday)
• Get the first day of the month
• Get the last day of the month
• Get the first day of the year
• Get the last day of the year
• Add or subtract days from a given date
• Get the ISO week number for a given date
• Format a date into a specific string pattern
• Get the day of the year for a given date
• Check if a given date is a weekend
• Check if a given year is a leap year