Date to Date Calculator computes the duration between two dates, including years, months, days, and optionally hours, minutes, and seconds. Input the start and end dates (and times if desired) and calculate the duration.

How to Use Date to Date Calculator:

1. Enter the start and end dates (YYYY-MM-DD) using the date picker or keypad; use “Next” to switch fields.
2. Optionally, enter times (HH:MM:SS) for precise duration including hours, minutes, and seconds.
3. Click “Calculate” to see step-by-step results.
4. Use “Share Result” to get shareable text or “Copy Result” to copy to clipboard.

Calculation Method:

Duration is calculated as the difference between two dates, accounting for leap years and varying month lengths. If times are provided, the duration includes hours, minutes, and seconds.

Important Notes:

• Both start and end dates must be valid and non-empty. The end date must not be earlier than the start date.
• Time inputs are optional; if omitted, the calculation assumes midnight (00:00:00).
• The calculator uses UTC to avoid timezone issues; ensure dates and times are entered consistently.
• Clipboard access requires a secure context (HTTPS). If copying fails, try accessing over HTTPS or copy manually.