function timeConversion(s) {
    // 07:05:45PM
    const timeInAmPmArray = s.split(/(AM|PM)/) // ['07:05:45', 'PM', '']
    const hour = Number(timeInAmPmArray[0].split(':')[0]) // 7
    const amOrPm = timeInAmPmArray[1] // PM
    let timeIn24Hour = ''
    if(amOrPm === 'AM') {
      timeIn24Hour = hour === 12 ? `00:${timeInAmPmArray[0].split(':').slice(1).join(':')}` : timeInAmPmArray[0]
    } else {
      timeIn24Hour = hour === 12 ? timeInAmPmArray[0] : `${hour + 12}:${timeInAmPmArray[0].split(':').slice(1).join(':')}`
      // timeIn24Hour = 19:05:45
    }
    return timeIn24Hour
}
    
timeConversion('07:05:45PM')