The number of days in 9 months can vary depending on which months you are counting because months have different lengths (28 to 31 days). However, here are some common ways to estimate:

1. Average Month Length Method

• Average month length = 30.44 days (365.25 days per year ÷ 12 months)
• 9 months ≈ 9 × 30.44 = 273.96 days ≈ 274 days

2. Using Exact Month Lengths

If you specify which months, you can add their exact days. For example, from January to September (9 months):

• Jan (31) + Feb (28 or 29) + Mar (31) + Apr (30) + May (31) + Jun (30) + Jul (31) + Aug (31) + Sep (30)
• Total (non-leap year) = 31 + 28 + 31 + 30 + 31 + 30 + 31 + 31 + 30 = 273 days
• In a leap year (Feb = 29 days), total = 274 days

3. Pregnancy Context

Pregnancy is often said to last about 9 months, which is roughly 280 days (40 weeks).

Summary:

• Average 9 months ≈ 274 days
• Exact months vary between 273 and 275 days
• Pregnancy duration ~280 days

Let me know if you want the calculation for specific months!