To calculate the exact and actual number of days between July 14, 2010, and December 20, 2012, we follow these steps:

1. Breaking down by years:

• From July 14, 2010 to July 14, 2011: This is a full year. Since 2011 is not a leap year, it contains 365 days.
• From July 14, 2011 to July 14, 2012: This is also a full year. Since 2012 is a leap year, it contains 366 days.

2. Handling the remaining days:

• From July 14, 2012 to December 20, 2012: We now calculate the number of days between these two dates.

  The months from July 14, 2012, to December 20, 2012, break down as:

  • July: 17 days (from July 14 to July 31)
  • August: 31 days
  • September: 30 days
  • October: 31 days
  • November: 30 days
  • December: 20 days (up to December 20)

Summing these days: $17 + 31 + 30 + 31 + 30 + 20 = 159 \text{ days}$

3. Total days:

Now, summing the days from all parts:

• 365 days (July 14, 2010 – July 14, 2011)
• 366 days (July 14, 2011 – July 14, 2012)
• 159 days (July 14, 2012 – December 20, 2012)

The total number of days is: $365 + 366 + 159 = 890 \text{ days}$

Thus, the exact and actual number of days between July 14, 2010, and December 20, 2012, is 890 days.

Would you like further details or have any other questions?

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Here are 5 related questions to further expand your understanding:

1. How do you calculate the number of days between two dates across leap years?
2. What are the rules to determine if a year is a leap year?
3. How does adding or subtracting days affect a given date?
4. How can we use date functions in programming languages like Python to compute such date differences?
5. How would the calculation differ if the end date was December 31, 2012?

Tip: When dealing with date calculations, always remember to account for leap years, which add an extra day in February (29 days instead of 28).