How a planned date is worked out

What this lesson is about

Every date on a critical path here is calculated, not typed. The app starts at the end of the order and counts backwards. It skips the days the factory does not work. Then it adds time for the things that make this order slower than an average one.

That last part is the surprise. A plan built from a ninety-day template can easily need far more than ninety days. The number in the template's name never changes to say so.

The anchor, and the direction of travel

A milestone's lead time is a number of days before ex-factory. Order confirmation on the basic knit spine carries a lead of ninety. Cargo ready carries two. So the plan is built from the ship end backwards, which is the right way round: the date the buyer cares about is fixed, and everything else has to fit in front of it.

The anchor is the order's ex-factory date. When that is empty the app uses the ship date instead, with no warning. The app itself expects about three weeks at sea on CIF terms, so a plan anchored on the ship date runs roughly that much too relaxed all the way through.

Counting back through a real calendar

The count is in working days, and two things are skipped.

The first is the factory's own rest days. Serageldin Knitwear rests on Friday and Saturday, which is stored on its factory record. The app's built-in default is Saturday and Sunday, and the settings screen offers a suggestion per country, including Friday and Saturday for Egypt. The suggestion is only a starting point. The factory's own setting always wins, and the working week the arithmetic uses is simply seven minus the number of rest days.

The second is factory holidays. That is a plain list of dates on /settings/ta that anyone with the Owner role can add to. A new workspace arrives with thirty-four Egyptian public holidays already in it, covering 2025 and 2026. The seeded list is candid that the Islamic dates are astronomical calculations, and that an official announcement can move them by a day. It is seeded for every workspace wherever the factory is, so a factory outside Egypt starts with somebody else's calendar.

Nine of those thirty-four fall inside the window this order occupies. Four of the nine land on a Friday or a Saturday, which the factory was not working anyway.

Five of the nine cost a day each. Those five days push the count across two more weekends, so the plan's start moves seven calendar days earlier than it otherwise would. Nobody has to work that out by hand. It is worth knowing that a holiday on a rest day is free, because half of them are.

The six stretches

A template is written for an average order. Yours is not average. Before any date is written, the app compares the template's built-in allowances against this order's real numbers. Where reality is bigger, it adds days.

There are six of these adjustments. Every one of them is zero when the data it needs is missing. Nothing is invented from an empty field.

Three words in that table need translating. A colourway is one colour version of the style. A lab dip is the small swatch a dyer sends for the buyer to approve the shade. SAM is the standard allowed minutes, meaning how long one garment takes to sew.

Each stretch carries a threshold, which is the lead time of the milestone it is protecting. It pushes back every milestone whose own lead is at or above that threshold. That is the whole trick. Extra time comes out of the front of the plan, and the tail between sewing and the container never moves against the ship date.

ORD-1274, one stretch at a time

STY-462 is a cotton polo with two colourways, total standard minutes of 15.5, no print, no embroidery and no wash. Its yarn comes from a spinner near Karacabey in Turkey with a recorded lead time of 38 days. Its trims come from Abu Hammad, an hour up the road, at 12 days. Serageldin's fastest line runs 1,600 pieces a day.

Read three of those closely. Each one shows the same idea from a different angle.

Material sourcing adds the overflow, not the lead. The longest supplier lead on the bill is the yarn at 38 days. Turkey is not the app's local country, so an imported premium of fourteen days is added, giving 52. The template already allows a sourcing runway: it books bulk yarn at 75 days out and expects it in the store at 32, so the runway is 43 days. The stretch is what will not fit, which is nine.

Development counts colours. Fourteen days are added when any colourway still needs a lab dip approved, and three more for every colourway after the first. Two colourways with one dip outstanding gives seventeen. A style with no colourways recorded at all gets nothing, because there is nothing left to be unapproved.

Complexity is worked out, not entered. A total of 15.5 standard minutes against a plain tee's baseline of twelve produces a factor of ×1.15, capped at 1.6. That factor lengthens the sampling block, and separately slows the sewing.

What that does to the dates

The stretches total thirty-seven days, and the milestone with the longest lead absorbs all of them.

Three things in that table are worth saying out loud.

1. The order had to start on 5 May, not the 30 June the template's ninety days would have given.
2. Everything from finishing onwards is untouched, exactly as the design intends.
3. The gap between booking the yarn and having it in the store is now 89 minus 37, which is 52 — the effective material lead, to the day.

The rest days matter as much as the stretches. The same 127 working days back from 5 November land on 30 April 2026 for a factory resting Saturday and Sunday, and on 6 June 2026 for one resting Friday only. The plan is not a property of the order alone.

I have a garment critical path whose dates are calculated rather than typed. Help me explain them to somebody who did not build the plan.

Paste or describe: the template name and its headline lead time, the order quantity, the fastest line's daily capacity, the longest supplier lead time on the bill, whether any material is imported, how many colourways still need a lab dip approved, and the style's total standard minutes.

Work out, showing each step: how many production days the quantity needs against the capacity, how much of that the template already allowed, and what is left over. Do the same for material sourcing. Then tell me, in one paragraph a factory owner would accept, why the order has to start when it does.