1360. Number of Days Between Two Dates LeetCode Solution

Last updated: February 23, 2025

In this guide, you will get 1360. Number of Days Between Two Dates LeetCode Solution with the best time and space complexity. The solution to Number of Days Between Two Dates problem is provided in various programming languages like C++, Java, and Python. This will be helpful for you if you are preparing for placements, hackathons, interviews, or practice purposes. The solutions provided here are very easy to follow and include detailed explanations.

Problem Statement
Complexity Analysis
Number of Days Between Two Dates solution in C++
Number of Days Between Two Dates solution in Java
Number of Days Between Two Dates solution in Python
Additional Resources

1360. Number of Days Between Two Dates LeetCode Solution image

Problem Statement of Number of Days Between Two Dates

Write a program to count the number of days between two dates.
The two dates are given as strings, their format is YYYY-MM-DD as shown in the examples.

Example 1:
Input: date1 = “2019-06-29”, date2 = “2019-06-30”
Output: 1
Example 2:
Input: date1 = “2020-01-15”, date2 = “2019-12-31”
Output: 15

Constraints:

The given dates are valid dates between the years 1971 and 2100.

Complexity Analysis

Time Complexity: O(1)
Space Complexity: O(1)

1360. Number of Days Between Two Dates LeetCode Solution in C++

class Solution {
 public:
  int daysBetweenDates(string date1, string date2) {
    return abs(daysFrom1971(date1) - daysFrom1971(date2));
  }

 private:
  const vector<int> days{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

  int daysFrom1971(const string& date) {
    const int year = stoi(date1.substr(0, 4));
    const int month = stoi(date1.substr(5, 2));
    const int day = stoi(date1.substr(8, 2));
    int res = 0;
    for (int i = 1971; i < year; ++i)
      res += isLeapYear(i) ? 366 : 365;
    for (int i = 0; i < month; ++i)
      res += days[i];
    if (month > 2 && isLeapYear(year))
      ++res;
    res += day;
    return res;
  }

  bool isLeapYear(int year) {
    return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
  };
};
/* code provided by PROGIEZ */

1360. Number of Days Between Two Dates LeetCode Solution in Java

class Solution {
  public int daysBetweenDates(String date1, String date2) {
    return Math.abs(daysFrom1971(date1) - daysFrom1971(date2));
  }

  private static final int[] days = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

  private int daysFrom1971(final String date) {
    final int year = Integer.valueOf(date.substring(0, 4));
    final int month = Integer.valueOf(date.substring(5, 7));
    final int day = Integer.valueOf(date.substring(8));
    int res = 0;
    for (int i = 1971; i < year; ++i)
      res += isLeapYear(i) ? 366 : 365;
    for (int i = 0; i < month; ++i)
      res += days[i];
    if (month > 2 && isLeapYear(year))
      ++res;
    return res + day;
  }

  private boolean isLeapYear(int year) {
    return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
  };
}
// code provided by PROGIEZ

1360. Number of Days Between Two Dates LeetCode Solution in Python

class Solution:
  def daysBetweenDates(self, date1: str, date2: str) -> int:
    days = [0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

    def isLeapYear(year: int) -> bool:
      return year % 4 == 0 and year % 100 != 0 or year % 400 == 0

    def daysFrom1971(date: str) -> int:
      year, month, day = map(int, date.split('-'))
      return (365 * (year - 1971) + sum(map(isLeapYear, range(1971, year))) +
              sum(days[:month]) + day + (month > 2 and isLeapYear(year)))

    return abs(daysFrom1971(date1) - daysFrom1971(date2))
 # code by PROGIEZ

Additional Resources

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