on time for exam

function onTimeForExam(input) {
    let examHH = Number(input.shift());
    let examMM = Number(input.shift());
    let arrivalHH = Number(input.shift());
    let arrivalMM = Number(input.shift());
    let distanceExam = (examHH * 60) + examMM;
    let distanceArrival = (arrivalHH * 60) + arrivalMM;
    let lateMM = 0;
    let lateHH = 0;
    if (distanceExam < distanceArrival) {
        console.log("Late");
        lateMM = distanceArrival - distanceExam;
        if (lateMM > 59) {
            lateHH = lateMM / 60;
            lateMM = lateMM % 60;
            if (lateMM > 9) {
                console.log(`${Math.floor(lateHH)}:${lateMM} hours after the start`)
            } else {
                console.log(`${Math.floor(lateHH)}:0${lateMM} hours after the start`)
            }
        } else {
            console.log(`${lateMM} minutes after the start`);
        }

    } else if (distanceExam > distanceArrival) {
        lateMM = distanceExam - distanceArrival;
    }
    if (lateMM <= 30) {
        console.log("On time");
        console.log(`${lateMM} minutes before the start`);
    } else {
        console.log("Early");
        if (lateMM > 59) {
            lateHH = lateMM / 60;
            lateMM = lateMM % 60;
            if (lateMM > 9) {
                console.log(`${Math.floor(lateHH)}:${lateMM} hours before the start`)
            } else {
                console.log(`${Math.floor(lateHH)}:0${lateMM} hours before the start`)
            }
        } else {
            console.log(`${lateMM} minutes before the start`);
        }
    }
}