chronia
    Preparing search index...

    Function addHours

    • Add the specified number of hours to the given date.

      This function validates arguments before processing and returns a new Date instance with the specified number of hours added. Fractional hours are truncated toward zero. Minutes, seconds, and milliseconds are preserved.

      Parameters

      • date: number | Date

        The base date as a Date object or timestamp (number)

      • amount: number

        The number of hours to add (can be negative to subtract)

      Returns Date

      A new Date object with the hours added, or Invalid Date if any input is invalid

      // Add positive hours
      const result = addHours(new Date(2020, 5, 15, 12, 0, 0), 3);
      // Returns: 2020-06-15 15:00:00

      // Subtract hours (negative amount)
      const result = addHours(new Date(2025, 8, 10, 15, 30, 0), -5);
      // Returns: 2025-09-10 10:30:00

      // Fractional amounts are truncated
      const result = addHours(new Date(2020, 0, 1, 12, 0, 0), 1.9);
      // Returns: 2020-01-01 13:00:00 (1.9 truncated to 1)

      // Crosses day boundary
      const result = addHours(new Date(2020, 0, 1, 23, 0, 0), 2);
      // Returns: 2020-01-02 01:00:00

      // Invalid inputs return Invalid Date
      const result = addHours(new Date("invalid"), 3);
      // Returns: Invalid Date
      • Validates arguments before conversion (consistent with library patterns)
      • Accepts both Date objects and numeric timestamps
      • Fractions are truncated using Math.trunc (1.9 → 1, -1.9 → -1)
      • Preserves minutes, seconds, and milliseconds
      • Returns Invalid Date for: Invalid Date, NaN, Infinity, -Infinity
      • Always returns a new Date instance (does not mutate input)

    Settings

    Member Visibility