As regards delivery of goods time is prima facie of the essence of the contract. See Hartley v. Hymans,  3 K. B. 475, referred to in chapter 5, 53.
The Sale of Goods Act (Ont. s. 29; U. K. s. 29) provides:
(4) Demand or tender of delivery may be treated as ineffectual unless made at a reasonable hour. What is a reasonable hour is a question of fact.
In the absence of an express provision in a contract of sale as to the time of delivery, a provision may be implied in some cases, as, for instance in the case of goods which to the know-ledge of the seller are needed for a certain purpose at a cer-tain time. If, however, there is no express or implied term requiring delivery at a certain time, the obligation of the seller is to deliver within a reasonable time. The question what is a reasonable time depends upon the actual existing circumstances, so that the time for delivery may be extended by circumstances necessarily involving delay, such as a strike, except in so far as the circumstances are caused or contributed to by the seller.
Hick v. Raymond,  A.C. 22; Sims v. Midland
By. Co.,  1 K.B. 103 ; Henry Hope & Sons v. Canada
Foundry Co., 1917, 40 O.L.R. 338, 39 D.L.R. 308. A contract for delivery of goods "at once" is a contract for delivery within a reasonable time.
Reg. v. Rogers, 1877, 3 Q.B.D. 28, at p. 33; Petrie v.
Rae, 1919, 46 O.L.R. 19. As to damages for non-delivery see chapter 8, 83.
Contracts for the sale of goods frequently require the performance of acts by a buyer before the obligation of deliv-ery falls upon the seller, for example, where the class of goods, the size or the quantities must be specified by the buyer. In such a contract where the words "as required," or the like words, do not appear, then upon the passing of a reasonable time the buyer will have lost his right to call upon the seller to deliver. Where the words "as required," or like words appear, then the contract does not come to an end merely by the lapse of a reasonable time it being necessary that the seller should have given notice to the buyer of his intention to put an end to the contract in the event of the buyer's not requiring delivery but even in the absence of such notice, the lapse of time may be so long as to induce the court to infer that it was the intention of both parties to abandon the contract.
Jones v. Gibbons, 1853, 8 Ex. 920, as explained in Pearl
Mill Co. v. Ivy Tannery Co.,  1 K.B. 78; see also
Sierichs v. Hughes, 1918, 42 O.L.R. 608, 43 D.L.R. 297.
If goods are to be delivered on the buyer's ship or "on car," the seller's obligation to deliver does not arise until the buyer has provided the ship or the car, and it may be expressly or impliedly agreed that notice shall be given by the buyer to the seller that the ship or the car is ready to receive the goods.
Armitage v. Insole, 1850, 14 Q.B. 728; Stanton v.
Austin, 1872, L.R. 7 C.P. 651; Stuart v. Clarke, 1917, 11
Alta. L.R. 551, 36 D.L.R. 254.