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Difference between two given times
• Difficulty Level : Medium
• Last Updated : 22 May, 2020

Given two times in string “HH:MM” format. Here ‘H’ shows hours and ‘M’ shows minutes. You have to find the difference in the same string format between these two strings. But both given strings should follow these cases.
1) Time 1 will be less than or equal to time2
2) Hours will be possible from 0 to 23.
3) Minutes will be possible from 0 to 59

Examples:

```Input : s1 = "14:00";
s2 = "16:45";
Output : result = "2:45"

Input : s1 = "1:04"
s2 = "13:05"
Output : result = "12:01"
```

## Recommended: Please try your approach on {IDE} first, before moving on to the solution.

The idea is to first remove colon. After removing colon, hour difference can be computed using simple mathematics.

## C++

 `// C++ program to find difference between two ` `// given times. ` `#include ` `using` `namespace` `std; ` ` `  `// remove ':' and convert it into an integer ` `int` `removeColon(string s) ` `{ ` `    ``if` `(s.size() == 4)  ` `        ``s.replace(1, 1, ``""``); ` `     `  `    ``if` `(s.size() == 5)  ` `        ``s.replace(2, 1, ``""``); ` `     `  `    ``return` `stoi(s); ` `} ` ` `  `// Main function which finds difference ` `string diff(string s1, string s2) ` `{ ` ` `  `    ``// change string (eg. 2:21 --> 221, 00:23 --> 23) ` `    ``int` `time1 = removeColon(s1); ` `    ``int` `time2 = removeColon(s2); ` ` `  `    ``// difference between hours ` `    ``int` `hourDiff = time2 / 100 - time1 / 100 - 1; ` ` `  `    ``// difference between minutes ` `    ``int` `minDiff = time2 % 100 + (60 - time1 % 100); ` ` `  `    ``if` `(minDiff >= 60) { ` `        ``hourDiff++; ` `        ``minDiff = minDiff - 60; ` `    ``} ` ` `  `    ``// convert answer again in string with ':' ` `    ``string res = to_string(hourDiff) + ``':'` `+ to_string(minDiff); ` `    ``return` `res; ` `} ` ` `  `// Driver program to test above functions ` `int` `main() ` `{ ` `    ``string s1 = ``"14:00"``; ` `    ``string s2 = ``"16:45"``; ` `    ``cout << diff(s1, s2) << endl; ` `    ``return` `0; ` `} `

## Python3

 `# Python 3 program to find difference between two  ` `# given times.  ` ` `  `# Remove ':' and convert it into an integer  ` `def` `removeColon(s): ` `     `  `    ``if` `(``len``(s) ``=``=` `4``): ` `        ``s ``=` `s[:``1``] ``+` `s[``2``:] ` `     `  `    ``if` `(``len``(s) ``=``=` `5``):  ` `        ``s ``=` `s[:``2``] ``+` `s[``3``:] ` `     `  `    ``return` `int``(s) ` ` `  `# Main function which finds difference  ` `def` `diff(s1, s2):  ` `     `  `    ``# Change string  ` `    ``# (eg. 2:21 --> 221, 00:23 --> 23)  ` `    ``time1 ``=` `removeColon(s1) ` `    ``time2 ``=` `removeColon(s2)  ` ` `  `    ``# Difference between hours  ` `    ``hourDiff ``=` `time2 ``/``/` `100` `-` `time1 ``/``/` `100` `-` `1``;  ` ` `  `    ``# Difference between minutes  ` `    ``minDiff ``=` `time2 ``%` `100` `+` `(``60` `-` `time1 ``%` `100``)  ` ` `  `    ``if` `(minDiff >``=` `60``): ` `        ``hourDiff ``+``=` `1` `        ``minDiff ``=` `minDiff ``-` `60` ` `  `    ``# Convert answer again in string with ':'  ` `    ``res ``=` `str``(hourDiff) ``+` `':'` `+` `str``(minDiff) ` `     `  `    ``return` `res ` ` `  `# Driver code ` `s1 ``=` `"14:00"` `s2 ``=` `"16:45"` ` `  `print``(diff(s1, s2)) ` ` `  `# This code is contributed by ApurvaRaj `

Output:

```2:45
```

This article is contributed by Harshit Agrawal. If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.