how to subtract specific part of time javascript momentjs

Question

I want to subtract a specific part of the time. I have timeSlot subtract by bookedSlot and duration and then return break slot array.

const timeSlots [{from: '10:00 am', to: '01:00 pm'}];
const bookedSlot = "12:00 pm"
const duration = "30min"

result need

const res = [
 {from: '10:00 am', to: '12:00 pm'},
 {from: '12:30 am', to: '01:00 pm'}
]

Answer 1

If I got your question correctly, this is some basic code you might consider as a solution for your problem. That's pretty rough solution, you might simplify it if you prefer.

function getFreeSlots(startInterval, endInterval, slotStartTime, slotDurationMin){
  var startTime = moment(startInterval, 'HH:mm');
  var endTime = moment(endInterval, 'HH:mm');
  var slotTime = moment(slotStartTime, 'HH:mm');
  var timeSlots = [];

  // we are going to add 1 day in case startTime > endTime 
  if(endTime.isBefore(startTime))
    endTime.add(1, 'day');

  // split interval into slots
  // first slot
  timeSlots.push({
    "from": startTime.format('HH:mm'),
    "to": slotTime.format('HH:mm')
  });
  
  var slotEndTime = slotTime.add(slotDurationMin, "minutes")
  // second slot
  timeSlots.push({
    "from": slotEndTime.format('HH:mm'),
    "to": endTime.format('HH:mm')
  });
  return timeSlots;
}

var res = getFreeSlots("10:00 am", "13:00 pm", "12:00 pm", 30);
console.log(res);

You might need to just add some transformer for

const duration = "30min"

so, you can pass some definite interval to the function.