// convertTo24HrsFormat("12:10AM") returns "00:10" // convertTo24HrsFormat("5:00AM") returns "05:00" // convertTo24HrsFormat("12:33PM") returns "12:33" // convertTo24HrsFormat("01:59PM") returns "13:59" // convertTo24HrsFormat("11:8PM") returns "23:08" // convertTo24HrsFormat("10:02PM") returns "22:02" const time = '5:00AM'; function convertTo24HrsFormat(time) { const slicedTime = time.split(/(PM|AM)/gm)[0]; let [hours, minutes] = slicedTime.split(':'); if (hours === '12') { hours = '00'; } let updateHourAndMin; function addition(hoursOrMin) { updateHourAndMin = hoursOrMin.length < 2 ? (hoursOrMin = `${0}${hoursOrMin}`) : hoursOrMin; return updateHourAndMin; } if (time.endsWith('PM')) { hours = parseInt(hours, 10) + 12; } return `${addition(hours)}:${addition(minutes)}`; } console.log(`Converted time: ${convertTo24HrsFormat(time)}`);