79-change-time-format

public String changeTimeFormat(String strTime) {
    Integer hrs = Integer.valueOf(strTime.substringbefore(':'));
    String meridiem = ' AM';
    String strHrs;
    if (hrs == 12) meridiem = ' PM';
    if (hrs > 12) { 
        meridiem = ' PM';
        hrs -= 12;
    }
    if (hrs == 0) {
        hrs = 12;
    }
    if(hrs<10){
        strHrs = '0' + String.valueOf(hrs);
    }
    else{
        strHrs = String.valueOf(hrs);
    }
    return strHrs + ':' + strTime.substringafter(':') + meridiem;
}