UVa 11309 - Counting Chaos (palindrome check)

Link: https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&category=25&page=show_problem&problem=2284
Sol:

#include <iostream>
	#include <string>
	using namespace std;
	void Tick(string& number)
	{
	number[3] += 1;
	if (number[3] > '9')
	{
	number[3] = '0';
	number[2] += 1;
	if (number[2] == '6')
	{
	number[2] = '0';
	number[1] += 1;
	if (number[1] > '9' || (number[0] == '2' && number[1] == '4'))
	{
	number[1] = '0';
	number[0] += 1;
	if (number[0] == '3')
	{
	number[0] = '0';
	}
	}
	}
	}
	}
	bool IsPalindrome(const string& number)
	{
	int start = 0, end = 3;
	while (number[start] == '0')
	++start;
	while (start < end)
	{
	if (number[start++] != number[end--])
	return false;
	}
	return true;
	}
	int main()
	{
	int T;
	cin >> T;
	string number;
	while (T--)
	{
	cin >> number;
	number.erase(2, 1);
	Tick(number);
	while (!IsPalindrome(number))
	Tick(number);
	cout << number[0] << number[1] << ':' << number[2] << number[3] << '\n';
	}
	}