js collection of date related functions

date-time.js

const initialDate = '07/29/2019';

export const monthsArray = ['January','February','March','April','May','June','July','August','September','October','November','December'];
export const dayNames = ['Sun', 'Mon', 'Tues', 'Wed', 'Thurs', 'Fri', 'Sat'];

/*
* @param padd Boolean - Add or not a 0 to the beginning of the number.
*/
export const getWeekDate = (padd) => {
    const currentDate = new Date(); // get current date
    const first = currentDate.getDate() - currentDate.getDay() + 1; // First day is the day of the week (Monday)
    const last = first + 6; // last day (friday) is the first day + 6

    const firstday = new Date(currentDate.setDate(first)).getDate();
    const lastday = new Date(currentDate.setDate(last)).getDate();

    if (padd) {
        return `${firstday.toString().padStart(2, 0)} - ${lastday.toString().padStart(2, 0)}`;
    }

    return `${firstday} - ${lastday}`;
};

/*
* This method gets the month (months) in the week.
*/
export const getMonthsInWeek = () => {
    const currentDate = new Date(); // get current date
    const firstDay = currentDate.getDate() - currentDate.getDay() + 1; // First day of the week (Monday)
    const lastDay = firstDay + 6; // last day (sunday) is the first day + 6
    const firstMonth = monthsArray[new Date(new Date().setDate(firstDay)).getMonth()];
    const lastMonth = monthsArray[new Date(new Date().setDate(lastDay)).getMonth()];
    
    return firstMonth === lastMonth ? `${firstMonth}` : `${firstMonth} - ${lastMonth}`;
};

export const clock = (el) => {
    let showColon = true;

    const buildClock = (showColon = true) => {
        const checkTime = (i) => i.toString().padStart(2, 0);
        const today = new Date();
        const h = today.getHours();
        let m = today.getMinutes();

        m = checkTime(m);

        const hTo12 = parseInt(h);
        return `${ checkTime(hTo12 > 12 ? hTo12 - 12 : hTo12) }${showColon ? ':' : ' '}${m} ${hTo12 > 11 ? 'pm' : 'am'}`;
    }

    if (el) {
        return setInterval(() => {
            showColon = !showColon;
            el.innerHTML = buildClock(showColon);
        }, 1000);
    }

    return buildClock();
}

export const currentDate = (date, dmy = false) => {
    const current_datetime = new Date();
    if (dmy) {
      return `${current_datetime.getDate().toString().padStart(2, 0)}/${(current_datetime.getMonth() + 1).toString().padStart(2, 0)}/${current_datetime.getFullYear()}`;
    }
  
    return `${(current_datetime.getMonth() + 1).toString().padStart(2, 0)}/${current_datetime.getDate().toString().padStart(2, 0)}/${current_datetime.getFullYear()}`;
}
    

export const isTodayOrFuture = (date) => {
    if(new Date(date) >= new Date(currentDay())){
        return true
    }

    return false;
}

export const sortByDate = (arr) => arr.sort((a, b) => new Date(a.date) - new Date(b.date));
export const sortByTime = (arr) => arr.sort((a, b) => new Date(`${a.date} ${a.hour}`) - new Date(`${b.date} ${b.hour}`));

export const hoursDifference = (to, from) => {
  const diff =(to.getTime() - from.getTime()) / 1000;
  diff /= (60 * 60);
    
  return Math.abs(Math.round(diff));
 }