To determine the number of days between January 1, 1971, and April 18, 2024, we’ll follow a systematic approach that accounts for both regular and leap years.

Step 1: Calculate the Total Number of Years

From January 1, 1971, to December 31, 2023, is 53 full years.

Step 2: Calculate the Number of Leap Years

Leap years are years divisible by 4, except for end-of-century years, which must be divisible by 400.
	•	Leap Years from 1971 to 2023:
	•	1972
	•	1976
	•	1980
	•	1984
	•	1988
	•	1992
	•	1996
	•	2000 (Note: Divisible by 400)
	•	2004
	•	2008
	•	2012
	•	2016
	•	2020
	•	Total Leap Years: 13

Step 3: Calculate Days from 1971 to 2023

	•	Total Days = (Number of Years × 365) + Number of Leap Days
	•	Total Days = (53 × 365) + 13
	•	Total Days = 19,345 + 13 = 19,358 days

Step 4: Calculate Days in 2024 up to April 18

Since 2024 is a leap year, February has 29 days.
	•	January: 31 days
	•	February: 29 days
	•	March: 31 days
	•	April: 18 days
	•	Total Days: 31 + 29 + 31 + 18 = 109 days

Step 5: Sum Total Days

	•	Total Days Between January 1, 1971, and April 18, 2024:
	•	19,358 days (from 1971 to 2023)
	•	+ 109 days (in 2024 up to April 18)
	•	= 19,467 days

Answer: 19,467 days