This is an action to recover an additional day’s pay under the terms of a collective bargaining agreement. The plaintiffs are the assignees of defendant’s employees.
Believing the instant case to be controlled by Local Union 9-2521, IWA-CIO, Plywood & Veneer Workers v. Aberdeen Plywood Corp., 47 Wn. (2d) 636, 289 P. (2d) 206, the trial court entered judgment for the plaintiffs, from which the defendant appeals.
Respondents contend the trial court was correct in so doing. The appellant contends to the contrary, and we agree.
In both cases, the claim for an extra day’s pay arose out of the fact that in 1954 the Fourth of July fell in the middle *767of the vacation period designated by the employers. Since the employees were on strike, none of them returned to work at the end of the vacation period. They were paid for the regular vacation, but not for an extra day on account of the holiday falling within the vacation.
The claim herein is dependent on the proper interpretation to be given to Articles VII and XV (g) of the agreement. They provide:
“Article VII — Holidays
“The following holidays shall be observed: Memorial Day, Fourth of July, Labor Day, Thanksgiving Day, New Year’s Day, . . . and Christmas Day . . . shall be recognized as paid holidays for qualified employees. . . . If a holiday falls on Sunday, the following Monday shall be recognized as the holiday. Holiday pay shall be eight (8) hours’ pay per holiday computed at the qualified employee’s regular job rate of pay for his regular work schedule.
“An employee is qualified for holiday pay if he has at least thirty-one (31) days’ seniority prior to the holiday and works the last regularly scheduled work day before and the first regularly scheduled work day after the ‘paid’ holiday. . . .
“Article XV — Vacations . . .
“g. If a holiday occurs during the calendar week in which the vacations are taken by any of the employees, one additional day’s vacation shall be taken because of such holiday by all individuals who are entitled to a complete vacation based on 1400 hours worked, but no additional day of vacation shall be granted to those who are taking vacations based on less than 1400 hours worked.” (Italics ours.)
Appellant contends that Article XV (g) does no more than extend a vacation by one day if a holiday happens to fall within it, and pay for that extra day is solely dependent on whether the individual employee qualifies for a paid holiday under Article VII. This is for the reason that the agreement elsewhere provides for precise pay schedules for vacations based on the number of hours worked by an individual employee during the preceding year.
Respondents contend that the employees qualify for an extra day’s pay for the Fourth of July under Article XV (g) because it extended the vacation period as such by one *768extra day, and, hence, they should be paid for it. This conclusion is predicated upon the theory that it must be inferred that the extra day of vacation automatically enlarges the precise provision for paid vacations by one day. This inference was allowed in the Local Union 9-2521 case, supra.
There is .a substantial difference between the instant case and the Local Union 9-2521 case, supra. The latter case was an appeal from a summary judgment, and the record contained no evidence of the facts prevailing when the agreement was made or the interpretation given it by the parties. The record in the instant case has a complete history of the agreement and the construction given to it by the parties.
In construing a contract, the intention of the parties must control (Crofton v. Bargreen, 53 Wn. (2d) 243, 332 P. (2d) 1081), and the interpretation which the parties to a contract have placed on it will be given great, if not controlling weight. Fancher v. Landreth, 51 Wn. (2d) 297, 317 P. (2d) 1066; 12 Am. Jur., Contracts, 787, § 249.
Since 1946 the language of Article XV (g) has remained unchanged. Prior to 1950, holidays were not paid for. From 1946 to 1950 employees were granted an extra day of vacation if a holiday fell within their vacation period, but in no instance were they paid for an extra day of vacation. In 1950, Article VII was modified to provide for paid holidays.
After 1950, employees were still granted an extra day of vacation if the holiday fell within their vacation period, but only those employees who qualified under Article VII were paid for the extra day. The appellant’s bookkeeping and payroll practices accurately reflected that practice. From 1946 through 1954 no objection to that practice was ever made. The first objection was made on December 29, 1955, following the publication of the Local Union 9-2521 case, supra. The undisputed record supports appellant’s contention that prior to 1955 the parties had uniformly followed its interpretation of the agreement that pay for holidays is governed solely by Article VII.
It is obvious that under Article VII none of the employees qualified for a paid holiday because of the Fourth *769of July falling in the period of his vacation for the reason that none of them returned to work on the first regularly-scheduled work day thereafter.
The trial court erred in not applying the interpretation of the collective bargaining agreement given it by the parties.
The judgment is reversed.
Weaver, C. J., Hill, Donworth, Finley, Ott, and Foster, JJ., concur.