1. What is the 90 Days Backwards Calculator?

This calculator determines the date that was 90 days before a specified date. It's useful for various time-based calculations in business, legal, medical, and personal contexts.

2. How Does the Calculator Work?

The calculator uses simple date arithmetic:

Where:

• Today — The reference date you input
• 90 days — The fixed period to subtract

Explanation: The calculation accounts for varying month lengths and leap years automatically.

3. Practical Applications

Details: Useful for calculating deadlines, expiration dates, medication schedules, or any 3-month period lookback requirements.

4. Using the Calculator

Tips: Enter any valid date in YYYY-MM-DD format. The calculator will automatically compute the date 90 days prior.

5. Frequently Asked Questions (FAQ)

Q1: Does this account for leap years?
A: Yes, the calculation automatically adjusts for leap years and varying month lengths.

Q2: Can I use this for business day calculations?
A: This calculates calendar days. For business days (excluding weekends/holidays), additional processing would be needed.

Q3: What's the maximum/minimum date range?
A: The calculator works with any valid date from 1970 through 2037 on most systems.

Q4: Can I calculate periods other than 90 days?
A: This calculator is specifically for 90 days. Other calculators are available for different time periods.

Q5: How precise is the calculation?
A: The calculation is precise to the day, but doesn't account for time of day in the calculation.