Shopify Estimated Delivery Date Snippet

{%- comment -%}
  Estimated delivery date, calculated in the shopper's browser so it never goes stale on a cached page.

{%- endcomment -%}
{%- liquid
  assign processing_days = 1
  
-%}
<ea-estimated-delivery
  data-tz="America/New_York"
  data-cutoff="14:00"
  data-processing="{{ processing_days }}"
  data-transit-min="3"
  data-transit-max="5"
  data-skip-weekends="true"
  data-holidays="2026-11-26,2026-12-25,2027-01-01"
  data-template="Get it by {date} if you order today"
></ea-estimated-delivery>
<script>
  if (!customElements.get('ea-estimated-delivery')) {
    customElements.define('ea-estimated-delivery', class extends HTMLElement {
      connectedCallback() { this.render(); }
      partsIn(date, tz) {
        var map = {};
        new Intl.DateTimeFormat('en-US', { timeZone: tz, hourCycle: 'h23', year: 'numeric', month: 'numeric', day: 'numeric', hour: 'numeric', minute: 'numeric' }).formatToParts(date).forEach(function (p) { map[p.type] = p.value; });
        return map;
      }
      render() {
        var tz = this.dataset.tz;
        var now;
        try { now = this.partsIn(new Date(), tz); } catch (e) { now = this.partsIn(new Date(), 'UTC'); }
        var cutoff = (this.dataset.cutoff || '14:00').split(':').map(Number);
        var afterCutoff = Number(now.hour) > cutoff[0] || (Number(now.hour) === cutoff[0] && Number(now.minute) >= cutoff[1]);
        var holidays = (this.dataset.holidays || '').split(',').filter(Boolean);
        var processingDays = Number(this.dataset.processing) || 0;
        var transitMin = Number(this.dataset.transitMin) || 0;
        var transitMax = Number(this.dataset.transitMax) || 0;
        var skipWeekends = this.dataset.skipWeekends === 'true';
        var startDays = processingDays + (afterCutoff ? 1 : 0);
        var base = new Date(Date.UTC(Number(now.year), Number(now.month) - 1, Number(now.day)));
        function addBusinessDays(date, days) {
          var d = new Date(date.getTime());
          var added = 0;
          var guard = 0;
          while (added < days && guard < 400) {
            d.setUTCDate(d.getUTCDate() + 1);
            guard++;
            var iso = d.toISOString().slice(0, 10);
            var dow = d.getUTCDay();
            if (skipWeekends && (dow === 0 || dow === 6)) continue;
            if (holidays.indexOf(iso) !== -1) continue;
            added++;
          }
          return d;
        }
        var minDate = addBusinessDays(base, startDays + transitMin);
        var maxDate = addBusinessDays(base, startDays + transitMax);
        var fmt = new Intl.DateTimeFormat(document.documentElement.lang || 'en-US', { weekday: 'short', month: 'short', day: 'numeric' });
        var text = transitMin === transitMax ? fmt.format(maxDate) : fmt.format(minDate) + '–' + fmt.format(maxDate);
        this.textContent = (this.dataset.template || 'Get it by {date}').replace('{date}', text);
      }
    });
  }
</script>