Estimated Arrival Line Item Properties

This document covers the line item properties used to calculate and display estimated arrival dates across the cart, checkout, and tracking page.

Overview

Estimated arrival dates for Made-to-Order (MTO) products flow through three systems:

Hydrogen Storefront - Sets initial properties when adding to cart
Platform Checkout Extension - Recalculates and updates properties at checkout
Theme Tracking Page - Reads properties to display arrival estimates

Line Item Properties

`_PRODUCTION_DAYS`

Raw number of production days for the item.

Attribute	Value
Set by	Hydrogen Storefront (cart)
Updated at checkout	No
Format	Integer string (e.g., `"56"`)
Used by tracking page	Yes (fallback calculation)

Source Priority:

Product's custom.production_days metafield
Site settings dualSale.standardProductionDays default

`_MADE-TO-ORDER`

Human-readable message with embedded delivery dates.

Attribute	Value
Set by	Hydrogen Storefront (cart)
Updated at checkout	No
Format	`"Expected to arrive between MM-dd-yyyy and MM-dd-yyyy"`
Used by tracking page	No (contains stale cart-time dates)

`_PROMISED_BY_DATE`

Human-readable message with embedded delivery dates, recalculated at checkout.

Attribute	Value
Set by	Hydrogen Storefront (cart)
Updated at checkout	Yes (recalculated)
Format	`"Expected to arrive between MM-DD-YYYY and MM-DD-YYYY"`
Used by tracking page	Yes (V2 parses dates from value)

`_MTO_DELIVERY_WINDOW`

The delivery window range in days (difference between upper and lower delivery estimates).

Attribute	Value
Set by	Hydrogen Storefront (cart)
Updated at checkout	No
Format	Integer string (e.g., `"7"`)
Used by tracking page	No

`_SHIPPING_SPEED`

Human-readable production timeline for display.

Attribute	Value
Set by	Hydrogen Storefront (cart)
Updated at checkout	No
Format	`"7-8 weeks"` or `"8 weeks"`
Used by tracking page	No

Calculation Logic

Hydrogen Storefront (Cart)

File: app/lib/cart.ts - prepareMTOProperties()

const productionDays = Number(productProperties?.productionDays)
  || siteSettings.dualSale.standardProductionDays;

const now = new Date();

// Upper bound: now + productionDays
const deliveryUpperEnd = new Date(now);
deliveryUpperEnd.setDate(deliveryUpperEnd.getDate() + productionDays);

// Lower bound: upperEnd - mtoDeliveryWindow
const mtoDeliveryWindow = resolveMtoDeliveryWindow(
  mtoDeliveryDays,
  siteSettings.dualSale.mtoDeliveryWindow
);
const deliveryLowerEnd = new Date(deliveryUpperEnd);
deliveryLowerEnd.setDate(deliveryLowerEnd.getDate() - mtoDeliveryWindow);

const deliveryMessage = mtoDeliveryWindow === 0
  ? `Expected to arrive ${format(deliveryUpperEnd, 'MM-dd-yyyy')}`
  : `Expected to arrive between ${format(deliveryLowerEnd, 'MM-dd-yyyy')} and ${format(deliveryUpperEnd, 'MM-dd-yyyy')}`;

// Both _MADE_TO_ORDER and _PROMISED_BY_DATE get the same value
attributes.push(
  { key: '_PRODUCTION_DAYS', value: productionDays.toString() },
  { key: '_MADE-TO-ORDER', value: deliveryMessage },
  { key: '_PROMISED_BY_DATE', value: deliveryMessage },
  { key: '_SHIPPING_SPEED', value: standardProductionTimeline },
  { key: '_MTO_DELIVERY_WINDOW', value: mtoDeliveryWindow.toString() }
);

Platform Checkout Extension

File: platform/extensions/item-attributes/src/Checkout.jsx

The checkout extension recalculates _PROMISED_BY_DATE based on the current time at checkout, ensuring accurate estimates if items sat in the cart.

// Triggers on each buyer journey step
useEffect(() => {
  for (const item of lineItems) {
    // Only update items with _MADE-TO-ORDER property
    if (item.attributes.some(attr => attr.key === '_MADE-TO-ORDER')) {
      // Fetch fresh production days
      const productionDays = await getProductionDaysMetafield(productId, query)
        || DEFAULT_MTO_PRODUCTION_DAYS;  // from delayed_delivery metaobject

      // Get delivery window from line item attributes (set by hydrogen-storefront)
      const deliveryWindow = getMtoDeliveryWindow(item.attributes);

      // Build message matching hydrogen-storefront format
      const promisedByDateMessage = buildPromisedByDateMessage(productionDays, deliveryWindow);

      // Update _PROMISED_BY_DATE (not _MADE-TO-ORDER)
      await updateLineItemPromisedByDateAttribute(item, promisedByDateMessage, applyCartLinesChange);
    }
  }
}, [buyerCurrentStep]);

Key behaviors:

Recalculates based on checkout time, not cart add time
Reads _MTO_DELIVERY_WINDOW from line item attributes (defaults to 7 if not present)
Updates only _PROMISED_BY_DATE, leaves _MADE-TO-ORDER unchanged
Format matches hydrogen-storefront: "Expected to arrive between..."

Tracking Page (V1)

File: theme/assets/tracking--order.js

V1 does not use _PROMISED_BY_DATE or parse dates from _MADE-TO-ORDER. Instead:

// Only uses shipping line code for MTO
if (isMTO) {
  const matchedShippingLine = this.order.shipping_lines.find(
    (shippingLine) => /(\d+)\s+weeks/.test(shippingLine.code)
  );
  if (matchedShippingLine) {
    const weeks = Number(/(\d+)\s+weeks/.exec(matchedShippingLine.code)[1]);
    estimatedDelivery.datetime_max = new Date(
      orderProcessed.getTime() + weeks * 7 * 24 * 60 * 60 * 1000
    );
    estimatedDelivery.type = "until";
  }
}

Tracking Page (V2)

File: theme/assets/tracking--order-v2.js

V2 parses dates from the _PROMISED_BY_DATE property value (recalculated at checkout):

const getMtoEDDFromLineItems = (lineItems) => {
  let earliestDate = null;
  let latestDate = null;
  let productionDays = null;

  for (const lineItem of lineItems) {
    for (const property of lineItem.properties) {
      const propertyName = String(property?.name || "").toUpperCase();
      const propertyValue = String(property?.value || "");

      if (propertyName === "_PROMISED_BY_DATE") {
        // Extract dates in MM-DD-YYYY format from the message
        const datePattern = /\b(\d{1,2})-(\d{1,2})-(\d{4})\b/g;
        for (const match of propertyValue.matchAll(datePattern)) {
          const [, monthStr, dayStr, yearStr] = match;
          const parsedDate = new Date(Date.UTC(
            Number(yearStr),
            Number(monthStr) - 1,
            Number(dayStr)
          ));
          if (!earliestDate || parsedDate < earliestDate) earliestDate = parsedDate;
          if (!latestDate || parsedDate > latestDate) latestDate = parsedDate;
        }
      } else if (propertyName === "_PRODUCTION_DAYS") {
        // Fallback: use production days to calculate
        const daysMatch = propertyValue.match(/\d+/);
        if (daysMatch) productionDays = parseInt(daysMatch[0], 10);
      }
    }
  }

  // Return based on what was found
  if (earliestDate && latestDate && earliestDate.getTime() !== latestDate.getTime()) {
    return { type: "range", datetime_min: earliestDate, datetime_max: latestDate };
  }
  if (latestDate) {
    return { type: "specific", datetime: latestDate };
  }
  if (Number.isFinite(productionDays)) {
    // Calculate from order date + production days
    const baseDate = new Date(order.processed_at || order.created_at || Date.now());
    return {
      type: "until",
      datetime_max: new Date(baseDate.getTime() + productionDays * 24 * 60 * 60 * 1000)
    };
  }
  return null;
};

Priority order:

Parse date range from _PROMISED_BY_DATE value (checkout-time dates)
Parse single date from _PROMISED_BY_DATE value
Calculate from _PRODUCTION_DAYS + order date (fallback)

Data Flow Summary

┌─────────────────────────────────────────────────────────────────────────────┐
│                           HYDROGEN STOREFRONT                                │
│                                                                             │
│  Add to Cart → prepareMTOProperties()                                       │
│                                                                             │
│  Sets:                                                                      │
│  • _PRODUCTION_DAYS = "56"                                                  │
│  • _MADE-TO-ORDER = "Expected to arrive between 01-15-2026 and 01-22-2026" │
│  • _PROMISED_BY_DATE = "Expected to arrive between 01-15-2026 and 01-22-2026"│
│  • _MTO_DELIVERY_WINDOW = "7"                                               │
│  • _SHIPPING_SPEED = "7-8 weeks"                                            │
└─────────────────────────────────────────────────────────────────────────────┘
                                      │
                                      ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                        PLATFORM CHECKOUT EXTENSION                          │
│                                                                             │
│  On buyer journey step change → updatePromisedByDate()                      │
│                                                                             │
│  Reads:                                                                     │
│  • _MTO_DELIVERY_WINDOW (defaults to 7 if not present)                     │
│                                                                             │
│  Updates (recalculates from checkout time):                                 │
│  • _PROMISED_BY_DATE = "Expected to arrive between 01-20-2026 and 01-27-2026"│
│                                                                             │
│  Unchanged:                                                                 │
│  • _MADE-TO-ORDER (still has cart-time dates)                              │
│  • _PRODUCTION_DAYS                                                         │
│  • _MTO_DELIVERY_WINDOW                                                     │
│  • _SHIPPING_SPEED                                                          │
└─────────────────────────────────────────────────────────────────────────────┘
                                      │
                                      ▼
┌─────────────────────────────────────────────────────────────────────────────┐
│                          THEME TRACKING PAGE                                 │
│                                                                             │
│  V1 (tracking--order.js):                                                   │
│  • Reads shipping_lines code only (e.g., "8 weeks")                        │
│  • Does NOT use _PROMISED_BY_DATE or _MADE-TO-ORDER                        │
│                                                                             │
│  V2 (tracking--order-v2.js):                                               │
│  • Parses dates from _PROMISED_BY_DATE value (checkout-time dates)         │
│  • Falls back to _PRODUCTION_DAYS calculation                              │
└─────────────────────────────────────────────────────────────────────────────┘

Important Notes

Date Format Consistency

All systems now use the same message format:

Source	Format Example
Hydrogen (cart)	`"Expected to arrive between 01-15-2026 and 01-22-2026"`
Platform (checkout)	`"Expected to arrive between 01-20-2026 and 01-27-2026"`

Delivery Window Calculation

All systems now use the same configurable delivery window from _MTO_DELIVERY_WINDOW.

Hydrogen Storefront

// app/lib/cart.ts

// Window comes from product or site settings (e.g., 7, 14, etc.)
const mtoDeliveryWindow = resolveMtoDeliveryWindow(
  Number(productProperties?.mtoDeliveryWindow),
  siteSettings.dualSale.mtoDeliveryWindow
);

// Sets _MTO_DELIVERY_WINDOW attribute for downstream use
attributes.push({ key: '_MTO_DELIVERY_WINDOW', value: mtoDeliveryWindow.toString() });

Platform Checkout Extension

// platform/extensions/item-attributes/src/Checkout.jsx

// Reads window from line item attributes (set by hydrogen-storefront)
const deliveryWindow = getMtoDeliveryWindow(item.attributes);
// Defaults to 7 if _MTO_DELIVERY_WINDOW not present

const message = buildPromisedByDateMessage(productionDays, deliveryWindow);

Comparison Table

System	Window Source	Lower Bound Formula	Upper Bound Formula
Hydrogen Storefront	`productProperties.mtoDeliveryWindow` or `siteSettings.dualSale.mtoDeliveryWindow`	`now + productionDays - mtoDeliveryWindow`	`now + productionDays`
Platform Checkout	`_MTO_DELIVERY_WINDOW` attribute (default: 7)	`now + productionDays - deliveryWindow`	`now + productionDays`
Theme cart.utils.js	Hardcoded `7`	`now + productionDays - 7`	`now + productionDays`

Production Days Source Differences

System	Primary Source	Fallback
Hydrogen	`productProperties.productionDays`	`siteSettings.dualSale.standardProductionDays`
Platform	`custom.production_days` metafield	`delayed_delivery` metaobject (`mto` or `matte-satin` handle)
Theme	`custom.production_days` metafield	`window.daysDelayedMto` (56) or `window.daysDelayedMatteSatin` (63)

Business Rules - Overall tracking page business logic
Production Timeline - MTO production timeline phases
UI & Display - Tracking page display logic

Hydrogen Storefront

app/lib/cart.ts - prepareMTOProperties() function
app/lib/constants.ts - Attribute key constants
app/components/ProductOptions/utils.tsx - calculatePromisedByDate() helper

Platform Repository

extensions/item-attributes/src/Checkout.jsx - Checkout extension that updates _PROMISED_BY_DATE
extensions/item-attributes/src/utils.js - Helpers: getMtoDeliveryWindow(), buildPromisedByDateMessage()

Theme Repository

assets/tracking--order.js - V1 tracking page (uses shipping line code)
assets/tracking--order-v2.js - V2 tracking page (parses _PROMISED_BY_DATE dates)
assets/cart.utils.js - Legacy cart utilities (Liquid theme)

Overview​

Line Item Properties​

_PRODUCTION_DAYS​

_MADE-TO-ORDER​

_PROMISED_BY_DATE​

_MTO_DELIVERY_WINDOW​

_SHIPPING_SPEED​

Calculation Logic​

Hydrogen Storefront (Cart)​

Platform Checkout Extension​

Tracking Page (V1)​

Tracking Page (V2)​

Data Flow Summary​

Important Notes​

Date Format Consistency​

Delivery Window Calculation​

Hydrogen Storefront​

Platform Checkout Extension​

Comparison Table​

Production Days Source Differences​

Related Documentation​

Related Files​

Hydrogen Storefront​

Platform Repository​

Theme Repository​

Overview

Line Item Properties

`_PRODUCTION_DAYS`

`_MADE-TO-ORDER`

`_PROMISED_BY_DATE`

`_MTO_DELIVERY_WINDOW`

`_SHIPPING_SPEED`

Calculation Logic

Hydrogen Storefront (Cart)

Platform Checkout Extension

Tracking Page (V1)

Tracking Page (V2)

Data Flow Summary

Important Notes

Date Format Consistency

Delivery Window Calculation

Hydrogen Storefront

Platform Checkout Extension

Comparison Table

Production Days Source Differences

Related Documentation

Related Files

Hydrogen Storefront

Platform Repository

Theme Repository