Hill, C. J.
When parties enter into a contract for the sale of personal property and name therein a time at which delivery is to take place, the question as to whether or not the time named is a material.part of the contract is a question to be decided in each case by a construction of the language used, in the light of the other relevant circumstances. Sneed v. Wiggins, 3 Ga. 94, 102; Civil Code, §3675 (8). As to the respective functions of the judge and the jury in such eases, see Civil Code, §§3672 et seq. The cardinal rule of interpretation is whether or not the parties *229intended that time should he oE the essence. “In contracts of merchants, time is of the essence. The time of shipment is the usual and convenient means of fixing the probable time of arrival, with a view of providing funds to pay for the goods, or of fulfilling contracts with third persons. A statement descriptive of the subject-matter, or some material incident, such as the time or place of shipment, is ordinarily to be regarded as a warranty, in the sense in which that term is used in insurance and maritime law, that is to say, a condition precedent, on the failure or non-performance of which the party aggrieved may repudiate the whole contract.” Norrington v. Wright, 115 U. S. 188, 203 (6 Sup. Ct. 12, 29 L. ed. 336); Cleveland Rolling Mills v. Rhodes, 121 U. S. 255, 261 (7 Sup. Ct. 882, 30 L. ed. 920), and cit.; McGrath v. Gegner, 77 Md. 331, 336 (26 Atl. 502, 39 Am. St. R. 415); 9 Cyc. 604. In the case at bar it is plain that the parties understood that time was a material term of the contract. This is shown by the letters; and even if they are not conclusive, the undisputed evidence removes all doubt on the question. In the véry first letter written, the plaintiff was specifically asked as to how promptly delivery of the lumber could be made; and the reply was that delivery would commence in two to three weeks. The defendant Walker testified at the trial that he told the plaintiff’s Atlanta manager, with whom most of the negotiations were carried on, that time was as much of an object as money, and was assured by him that his principal would keep the stipulation as to time, without fail. See Savannah Ice Co. v. Amer. Refrigerator Transit Co., 110 Ga. 142, 145 (35 S. E. 280). It therefore follows that the plaintiff was guilty of a breach of the contract, by not delivering the lumber within the time limited. According to the contract, delivery was to commence in two to three weeks; and the evidence shows that no part of the lumber was delivered within seven to eight weeks. For a breach of this term of the contract, the defendants could have treated the contract as at an end, and have instituted suit for damages caused by non-performance on the part of the sellers. This they did not do; but wrote to the plaintiff complaining of the breach and. stating that they would be damaged thereby in various ways, for all of which they would hold the plaintiff responsible. The plaintiff replied, expressly repudiating liability under the contract, for the items of damage claimed. *230After the receipt of this letter, the defendants wrote, on August 19, “If you will get us this material promptly, however, there will be no question about damages of any kind, apd we trust you will do so.” In view of the previous negotiations, this letter could mean but one thing, namely, the defendants were willing to waive all claim for damages growing out of the plaintiff’s non-performance within the time limited, if thereafter the lumber should be delivered promptly. That this was the purpose of the letter is further brought out by the testimony of Walker at the trial. He says: “On August 19th, I wrote this letter stating that there would be no question about damages if the material was promptly coming; if it came promptly I would not hold them for damages. That was a further inducement to get it here. Now that was after the time for delivery. That was after I found that I could not get it promptly anywhere else.” It is equally plain from the letter, as well as from the undisputed evidence, that the offer to waive was not absolute or unconditional; it was expressly conditioned upon the plaintiff’s thereafter delivering the lumber promptly. See McCroskey v. Hamilton 108 Ga. 646 (34 S. E. 111, 75 Am. St. R. 79). The defendants, in effect, said, “We offer to waive or renounce our claim for damages growing out of your breach, in consideration of your hereafter promptly delivering to us the lumber.” It will thus be seen that the letter, in and of itself, was nothing more than an offer; and that it needed a consideration, to make it binding. The consideration contemplated was the subsequent prompt delivery of the lumber by the plaintiff. The plaintiff was not legally bound to deliver the lumber at any other time than that mentioned in the original contract; and his delivery of the same at a subsequent time would be a good consideration for the defendants’ offer to renounce the claim for damages, and would have the effect of enlarging the time within _ which the lumber could be -delivered. Stryker v. Vanderbilt, 25 N. J. L. (1 Dutcher) 482 (2); Teal v. Bilby, 123 U. S. 572 (8 Sup. Ct. 239, 31 L. ed. 263); Thornhill v. Neats, 8 C. B. N. S. 831 (98 Eng. C. L. 539); Pinckney v. Dambmann, 72 Md. 173 (19 Atl. 450); Mfg. Co. v. U. S., 17 Wall. 592 (21 U. S. (L. ed.) 715); Cornish v. Suydam, 99 Ala. 620 (13 So. 118). The learned trial judge, however, held that the letter itself was a complete waiver. In doing so he overlooked the fact that it was expressly *231conditioned as above indicated, and that until tbe condition had been complied with, it was a nudum pactum. Bennett v. Hyde, 92 Cal. 134 (28 Pac. 104); McCarter v. Turner, 49 Ga. 311; Fowler v. Coker, 107 Ga. 820 (35 S. E. 661). The defendants contend that the plaintiff did not comply with its offer and did not deliver the lumber promptly thereafter. This letter was written on August 19; the final instalment of the lumber was not shipped until some time in November or December. Whether or not this was a compliance with the condition upon which the defendants made their offer to waive is, under the evidence in the ease, a question for the jury, to be determined by them in the light of all the surrounding circumstances and the exigencies of the contracting parties. Fitzgerald Cotton Oil Co. v. Farmers Supply Co., 3 Ga. App. 212 (2), (59 S. E. 713); 9 Cyc. 611. Under some circumstances it might be called a prompt delivery, and under others it would not. In view of the evidence in the record, reasonable men might draw different inferences as to whether the deliveries made after the letter of August 19 were prompt or not. It was therefore a question for the jury, and not for the judge; and he erred in directing a verdict for 'the plaintiff.
But counsel for the plaintiff argues that the mere acceptance of the property, under the circumstances, was a waiver, whether the deliveries were promptly made or not; and he cites cases wherein it was held that the forfeiture of an insurance policy was waived by an acceptance of the overdue premium, and eases where, by accepting overdue rent, a landlord was held to have waived the clause in the lease as to forfeiture. That such a principle is not applicable to an ordinary contract for the sale of personal property is not now an open question in this State. Van Winkle v. Wilkins, 81 Ga. 94 (7), 104 (7 S. E. 644, 12 Am. St. R. 299). In that case Judge Bleckley says: “It was urged in argument that receiving the machinery was a waiver both of its defects and of damages resulting from its non-delivery in due time. Why' so? After expensive preparation to have and use a mill, it was probably much better to have one of inferior quality than none at all. . . As to the damages resulting from delay, these had already been sustained when the mill was received; its reception, in so far as it affected them at all, could only hinder more from accruing; it certainly could not increase them. There was no inconsistency *232between reception of tlie machinery and retention of the claim Tor damages on account of delay to furnish it by the time stipulated. To hold that there was a waiver by implication would be very unreasonable.” See also Poland Paper Co. v. Foote & Davies Co., 118 Ga. 458; Sneed v. Wiggins, 3 Ga. 94, 103; Underwood v. Wolf, 131 Ill. 425 (9), 442 (23 N. E. 598, 19 Am. St. R. 40); 2 Mechem on Sales, §1389; Dermott v. Jones, 23 How. 220 (16 U. S. (L. ed.) 442). In Perry Tie Co. v. Reynolds, 100 Va. 264 (40 S. E. 919), the vendees of lumber, as in this ease, accepted it after the time for delivery had gone by, and the vendors claimed that such acceptance was a waiver of damages for non-delivery within the time limited. The court, however, held: “The acceptance by a vendee of a late delivery will not be deemed a waiver of the consequent damages sustained by him, where it appears that there was no intention to waive such damages.” The only intention to waive damages, appearing in the case at bar, is the letter of August 19; and the intention there expressed was limited by a condition to be performed by the vendors. The waiver should be carried no further than the intention. See Phillips & Colby Construction Co. v. Seymour, 91 U. S. 646, 651 (23 L. ed. 341). It would do violence to the plain and unequivocal intention of the defendants, as expressed in their letters and as shown by their prior and subsequent conduct, to hold that they had made an absolute waiver of damages, merely by accepting the lumber, unless the acceptance was within a reasonable time after the letter of August 19 was written. Judgment reversed.