date-fns breaking changes

4.0.0

403 breaking changes, first published September 16, 2024.

• Behavior changed
  The package is now published ESM-first. CommonJS still works but may break in some environments, so check your module setup if you hit problems. github.com
• Signature changed
  Types changed in ways that mainly affect code that explicitly uses date-fns internal types. Run the TypeScript type checker after upgrading and fix any errors it reports. github.com
• Signature changed add
  Was function add<DateType extends Date>(date: DateType | number | string, duration: Duration): DateType; now function add<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, duration: Duration, options?... npmjs.com
• Signature changed addBusinessDays
  Was function addBusinessDays<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addBusinessDays<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount... npmjs.com
• Signature changed addDays
  Was function addDays<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addDays<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount: number, options?... npmjs.com
• Signature changed addHours
  Was function addHours<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addHours<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount: number, options?... npmjs.com
• Signature changed addISOWeekYears
  Was function addISOWeekYears<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addISOWeekYears<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount... npmjs.com
• Signature changed addMilliseconds
  Was function addMilliseconds<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addMilliseconds<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount... npmjs.com
• Signature changed addMinutes
  Was function addMinutes<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addMinutes<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount: number... npmjs.com
• Signature changed addMonths
  Was function addMonths<DateType extends Date>(date: DateType | number | string, amount: number): DateType; now function addMonths<DateType extends Date, ResultDate extends Date = DateType>(date: DateArg<DateType>, amount: number, options?... npmjs.com

And 393 more in this version.

Check your code

These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.