Create a calendar application to check the scheduling conflicts of meetings The purpose here is to find if there is a conflict in the given set of start and end times of the meeting time slots listed.

Input: Start and end times of meetings

Output: True / False for conflicts

package code.Misc;

import java.util.ArrayList;

public class Calendar {

static int time [] = new int[1440];

public static void main(String args[]){

    String s[] =   {"15:30","1:30","1:15","15:00"};
    String e[] = {"18:35","13:28","1:30","15:29"};

    System.out.println(scheduler(s, e));
}

public static int calculateMinute(int hour, int minute){
        return hour*60+minute;
}

public static boolean timeClashChecker(int start, int end){
        for(int i=start;i&lt;=end;i++){
            if(i==end){
                time[i] =  -1;
            }
            else if(time[i]==1){
                return false;
            }
            else if(time[i]==-1){
                time[i]=1;
            }
            else{
                time[i]=1;
            }
        }
    return true;
}
public static int parser(String time){
    String [] timeParts = time.split(":");
    int hour = Integer.parseInt(timeParts[0].trim());
    int minute = Integer.parseInt(timeParts[1].trim());

    return calculateMinute(hour,minute);
}
public static boolean scheduler(String start[], String end[]){

    for(int i=0;i&lt;start.length;i++){
        int startMeeting = parser(start[i]);
        int endMeeting = parser(end[i]);
        boolean result = timeClashChecker(startMeeting,endMeeting);
        if(result == false){ //clash check
            return false;
        }
    }
    return true;
}
}
A couple of things that would be good to point out:


It appears that your code only checks the clash between the start and end time. If the start time is always bigger than the end time, in theory it should never clash. 

for(int i=0;i&lt;start.length;i++){
    int startMeeting = parser(start[i]);
    int endMeeting = parser(end[i]);
    boolean result = timeClashChecker(startMeeting,endMeeting);
    if(result == false){ //clash check
        return false;
    }
}


might be replaced with:

for(int i=0;i&lt;start.length;i++){
    int startMeeting = parser(start[i]);
    int endMeeting = parser(end[i]);
    for(int e = 0; e &lt; end.length; e++){
        if(e == i) continue;
        int meetingEnd = parser(end[e]);
        if(meetingEnd &gt; startMeeting &amp;&amp; meetingEnd &lt; endMeeting) return true;
    }

    for(int s = 0; s &lt; start.length; s++){
        if(s == i) continue;
        int meetingStart = parser(start[s]);
        if(meetingStart &gt; startMeeting &amp;&amp; meetingStart &lt; endMeeting) return true;
    }

}



This way the end of each meeting is checked with each starting time. If there is a clash with any of them, it should detect it. It also checks if each starting time of another is also between a meeting.


If you make the change above, your timeClashChecker method is unnecessary. 
Some of the method names are not entirely helpful.parser could become parseTime, and scheduler could be changed to doesClash, especially seeing it doesn't do any of the scheduling itself.