Given two strings **str1** and **str2** which represent two dates, the task is to count the number of days between given two dates. Given that dates given are beyond 1971.

**Examples:**

Input:str1 = “2020-01-29”, str2 = “2020-01-30”Output:1Explanation:

The number of days between 29^{th}January and 30^{th}January is 1.

Input:str1 = “1971-06-29”, str2 = “2019-06-23”Output:17526

**Approach:** The idea is to convert both the dates into its respective seconds. Since there are 86, 400 seconds in a day, the number of days between both the days can be found out by dividing the difference of seconds with 86, 400.

Below is the implementation of the above approach:

`// C++ implementation of the above approach` `#include <iostream>` `#include <sstream>` `#include <string>` `using` `namespace` `std;` ` ` `// Function to find the number of days` `// between given two dates` `int` `daysBetweenDates(string date1, string date2)` `{` ` ` `stringstream ss(date1 + ` `"-"` `+ date2);` ` ` `int` `year, month, day;` ` ` `char` `hyphen;` ` ` ` ` `// Parse the first date into seconds` ` ` `ss >> year >> hyphen >> month >> hyphen >> day;` ` ` `struct` `tm` `starttm = { 0, 0, 0, day,` ` ` `month - 1, year - 1900 };` ` ` `time_t` `start = ` `mktime` `(&starttm);` ` ` ` ` `// Parse the second date into seconds` ` ` `ss >> hyphen >> year >> hyphen` ` ` `>> month >> hyphen >> day;` ` ` `struct` `tm` `endtm = { 0, 0, 0, day,` ` ` `month - 1, year - 1900 };` ` ` `time_t` `end = ` `mktime` `(&endtm);` ` ` ` ` `// Find out the difference and divide it` ` ` `// by 86400 to get the number of days` ` ` `return` `abs` `(end - start) / 86400;` `}` ` ` `// Driver code` `int` `main()` `{` ` ` `string str1 = ` `"2019-09-12"` `;` ` ` `string str2 = ` `"2020-08-04"` `;` ` ` `cout << daysBetweenDates(str1, str2);` ` ` `return` `0;` `}` |

**Output:**

327

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