The check, before the packets are printed
Updated
On this page8
One: when was the germination test completed?
Month and year, from the laboratory report. The window runs from the last day of that month: five calendar months to interstate shipment, or twenty-four if the seed is in a hermetically sealed container and the test preceded packaging.
Two: does the result meet the standard for the crop?
Look it up in 7 CFR 201.31. Carrot 55, lettuce 80, turnip 80, pepper 55, and about seventy-five entries. At or above and under a pound, the percentage and date need not appear; below it, "Below Standard" does, at 8 points or larger.
Three: what does a filled container weigh?
Weighed, not computed from capacity, because seed density varies by crop. Over one pound the germination figures and a lot number are required regardless of the standard. The same jar can be on either side for two different crops.
Four: is it hermetically sealed, and can you prove it?
That is a question about your filled package and your sealing process, not about a closure part number. If the twenty-four month window is part of the plan, settle it before the production schedule depends on it.
Five: has the seed been treated?
If so, the label carries the treatment disclosure in type no smaller than 8 point with the substance or process named, and more where the residue is harmful. If you are repackaging, get that information from the supplier in writing.
Then record the window per lot
Lot, crop, test month, window end date, sealed or not. Nothing in the warehouse signals the date passing, and a calendar is the only control that works.
And keep retained samples
Sealed from each packing run, stored as the stock is stored, and germinated later. The laboratory tested your seed; a retained sample tests your package, and only one of those is under your control.