Add / Subtract Time

## Project Into the Future (or Past)
"What is the date 45 days from today?" or "If I subtract 3 weeks from the launch date, when do we need to start?" The **Add / Subtract Time** tool answers these questions instantly.

### Why do I need this?
- **Deadlines**: Calculate the exact submission date for a project (e.g., "Net 30 days").
- **Cooking**: "If the turkey needs 3 hours and 20 minutes and dinner is at 6:00 PM, when should I put it in?"
- **Legal**: Determine when a warranty or contract expires (e.g., exactly 2 years from purchase).

### Features
- **Multi-Unit Math**: Add years, months, weeks, days, hours, and minutes all at once.
- **Smart Rollover**: Adding 90 minutes automatically increases the hour count. Adding 40 days automatically flips the month.
- **Instant Feedback**: The result updates in real-time as you type.

### Accuracy
We handle the complexities of the Gregorian calendar for you:
- Varying month lengths (28, 30, 31 days).
- Leap years (extra day in February).