Appointment Time Finder

appointment-time-finder.js

function getStartTime(schedules, duration) {
  //console.log('schedules:', schedules, '| duration:', duration);
  let spareTime = [];
  schedules.forEach((schedule, index) => {
    //console.log('index:', index);
    spareTime.push([]);
    if (schedule.length > 0) { // if a whole day is free schedule.length === 0
      //console.log('schedule[0]:', schedule[0]);
      if ((parseInt(schedule[0][0].split(':')[0]) > 9 && parseInt(schedule[0][0].split(':')[1]) >= 0) || (parseInt(schedule[0][0].split(':')[0]) >= 9 && parseInt(schedule[0][0].split(':')[1]) > 0)) {
        //console.log('extra time in the morning, checking duration:', schedule[0][0]);
        const diff = (parseInt(schedule[0][0].split(':')[0]) - 9) * 60 + parseInt(schedule[0][0].split(':')[1]);
        //console.log('diff:', diff);
        if (diff >= duration) { spareTime[index].push(['09:00', schedule[0][0]]); }
        //console.log('spareTime:', spareTime);
      }
      
      for (let i = 1, max = schedule.length; i < max; i++) {
        const previous = schedule[i - 1];
        const current = schedule[i];
        const diff = (parseInt(current[0].split(':')[0]) - parseInt(previous[1].split(':')[0])) * 60 + parseInt(current[0].split(':')[1]) - parseInt(previous[1].split(':')[1]);
        //console.log('diff:', diff);
        if (diff >= duration) { spareTime[index].push([previous[1], current[0]]); }
      }
      const lastIndex = schedule.length - 1;
      if (parseInt(schedule[lastIndex][1].split(':')[0]) < 19) {
        //console.log('extra time in the evening, checking duration:', schedule[lastIndex][1]);
        const diff = (19 - parseInt(schedule[lastIndex][0].split(':')[0])) * 60 + 60 - parseInt(schedule[lastIndex][0].split(':')[1]);
        //console.log('diff:', diff);
        if (diff >= duration) { spareTime[index].push([schedule[lastIndex][1], '19:00']); }
      }
    } else {
      spareTime[index].push('09:00', '19:00');
    }
  });
  console.log('spareTime:', spareTime);
  const noSpareTime = spareTime.filter((schedule) => schedule.length === 0);
  if (noSpareTime.length > 0) {
    //console.log('noSpareTime:', noSpareTime);
    return null;
  }
  const mostAvailable = spareTime.reduce((a, b) => { return (a.length < b.length) ? b : a; });
  //console.log('mostAvailable:', mostAvailable);
  spareTime.splice(spareTime.indexOf(mostAvailable), 1);
  //console.log('spareTime:', spareTime);
  let matches = 0;
  let matchesDetails = [];
  let time = null;
  root:
  for (let k = 0, kMax = mostAvailable.length; k < kMax; k++) {
    const sch0 = mostAvailable[k];
    //console.log('sch0:', sch0);
    let sch0Start = parseInt(sch0[0].split(':')[0]) * 60 + parseInt(sch0[0].split(':')[1]);
    if (matchesDetails.length > 0) {
      sch0Start = (matchesDetails[matchesDetails.length - 1].time && time > sch0Start) ? matchesDetails[matchesDetails.length - 1].time : sch0Start;
    }
    const sch0End = parseInt(sch0[1].split(':')[0]) * 60 + parseInt(sch0[1].split(':')[1]);
    //console.log('sch0:', sch0Start, sch0End);
    matches = 0;
    time = null;
    child1:
    for (let j = 0, jMax = spareTime.length; j < jMax; j++) {
      const schedule = spareTime[j];
      //console.log('NEXT SCHEDULE:', schedule);
      child2:
      for (let i = 0, max = schedule.length; i < max; i++) {
        const start = parseInt(schedule[i][0].split(':')[0]) * 60 + parseInt(schedule[i][0].split(':')[1]);
        const end = parseInt(schedule[i][1].split(':')[0]) * 60 + parseInt(schedule[i][1].split(':')[1]);
        //console.log('schedule time in minutes', start, end);
        if (sch0Start <= start && sch0End >= end) {
          matches++;
          time = (time < start) ? start : time;
          matchesDetails.push({ time: time, gaps: [start, end] });
          //console.log('break child2 1, time', time);
          break child2;
        } else if (sch0Start > start && sch0End >= end && end > sch0Start && end - sch0Start >= duration) {
          matches++;
          time = (time < sch0Start) ? sch0Start : time;
          matchesDetails.push({ time: time, gaps: [start, end] });
          /*
          console.log('break child2 2, time', time);
          console.log('diff', end - sch0Start);
          console.log('schedule 0:', sch0Start, sch0End, '|', duration);
          console.log('schedule '+i+':', start, end, '|', duration);
          */
          break child2;
        } else if (sch0Start > start && sch0End < end  && end - sch0Start >= duration && sch0End - start >= duration) {
          matches++;
          time = (time < sch0Start) ? sch0Start : time;
          matchesDetails.push({ time: time, gaps: [start, end] });
          /*
          console.log('break child2 3, time', time);
          console.log('diff', sch0End - start);
          console.log('schedule 0:', sch0Start, sch0End, '|', duration);
          console.log('schedule '+i+':', start, end, '|', duration);
          */
          break child2;
        } else if (sch0Start <= start && start < sch0End && sch0End < end  && sch0End - start >= duration) {
          matches++;
          time = (time < start) ? start : time;
          matchesDetails.push({ time: time, gaps: [start, end] });
          /*
          console.log('break child2 3, time', time);
          console.log('diff', sch0End - start);
          console.log('schedule 0:', sch0Start, sch0End, '|', duration);
          console.log('schedule '+i+':', start, end, '|', duration);
          */
          break child2;
        } else {
          console.log('ignore');
          /*
          console.log('schedule 0:', sch0Start, sch0End, '|', duration);
          console.log('schedule '+i+':', start, end, '|', duration);
          */
        }
      }
      //console.log('matches:', matches, '| schedules.length:', schedules.length);
      //console.log('===');
      if (schedules.length - 1 === matches && sch0End - time >= duration) {
        //console.log('break root, time', time);
        //console.log('schedule 0:', sch0Start, sch0End, '|', duration);
        matches++;
        break root;
      }
    }
  }
  //console.log('matchesDetails:', matchesDetails, 'time:', time);
  // recalculate suitable matches after finding earlies starting time possible
  matches = 1;
  matchesDetails.forEach((match) => {
    if (match.gaps[1] - time >= duration) { matches++; }
  });
  if (schedules.length !== matches) { time = null; }
  // convert result to format hh:mm
  let hours = Math.floor(time / 60);
  hours = (hours < 10) ? '0' + hours : hours;
  let minutes = time % 60;
  minutes = (minutes < 10) ? '0' + minutes : minutes;
  return (time) ? hours + ':' + minutes : time;
}

let schedules = [
  [['09:10', '11:30'], ['12:30', '16:30'], ['17:30', '19:15']],
  [['09:15', '12:10'], ['14:10', '16:20']]
],
    duration = 120;
getStartTime(schedules, duration); // null

AppointmentTimeFinder.markdown

Appointment Time Finder

Searches provided schedules of apointments for spare time gaps. Checks whether found time gaps fullfill a provided duration requirement. Possible time for appointment is 09:00 - 19:00 excluding ending time. Next appointment can be scheduled at 11:30 if previous apointment ends at 11:30 accorging to provided schedule. Returns earliest possible time for an appointment in format hh:mm or null if nothing was found.

Input schedule example

Person	Meetings
A	09:10 - 11:30, 12:30 - 16:30, 17:30 - 19:15
B	09:15 - 12:10, 14:10 - 16:20

The scehdule is provided as a three dimensinal array, i.e.:

[
  [['09:10', '11:30'], ['12:30', '16:30'], ['17:30', '19:15']],
  [['09:15', '12:10'], ['14:10', '16:20']]
]

A script by V.

License.