在某些类型的雇佣中，只需说明所雇佣的工作类型即可，例如缝纫，或驾车前往某个指定地点，而无需说明时间长短。在另一些类型的雇佣中，则只需说明雇佣的时间长度，而无需说明工作量。例如，雇人一个月挖井或挖渠，就属于这种情况。

In some types of hiring, it is necessary to mention only the type of work hired for, such as sewing, or driving a car to a named place, without mentioning a duration. In other types of hiring, it is necessary to mention only the duration of hiring, without mentioning the quantity of work. An example of this is to hire somebody for a month to dig a well or a canal,

对于那些不需要规定数量、只需在此月内进行挖掘即可的情况，无论工作量多少，都是如此。而在其他类型的工作中，则必须说明工期和工作的类型，例如建造房屋、建设炼油厂等。因此，凡是需要界定时间期限的工作，都必须注明该期限。

which does not need a quantity defined, only that the digging should be done during this month, whether little or much. In other types, the duration and the type of work have to be mentioned, such as building a house, constructing an oil refinery and the like. So every work that needs the time period to be defined, the time period has to be mentioned,

因为雇佣的性质必须是已知的。如果在某些作品中没有提及时间期限，雇佣就会变得不明确，而雇佣不明确则无效。如果雇佣是约定一个确定的时间段，例如一个月或一年，那么双方中的任何一方在时间段结束之前都不得擅自违约、解除雇佣合同。如果工人是按重复的时间段受雇的，例如每月二十第纳尔，那么他必须每个月都参与约定的工作，并且雇佣合同中必须注明期限。雇佣期限（即那个月）不一定要紧接合同签订后开始。因此，允许在穆哈兰月雇佣某人，让他在赖哲卜月工作。如果合同中提及了期限，或者为了消除不确定性而有必要提及，那么这一时间段必须以时间单位来界定，例如分钟、小时、周、月或年。

because the nature of the hiring has to be known. Not mentioning the time duration in some works makes the hiring unknown, and if the hiring is unknown it becomes invalid. If the hiring was contracted over a certain time period such as one month or one year, then no one of the two parties is allowed to break the contract of hiring until the time period has ended. If a worker was hired for a repeated time duration, such as twenty dinars monthly, then he has to be involved in the contracted work every month and the duration must be mentioned in the hiring contract. It is not necessary that the period of hiring (i.e. the month) has to start immediately after the contract. So it is allowed to hire a person in Muharram to work in Rajab. If the duration was mentioned in the contract or it was necessary to mention it so as to remove uncertainty, then this time period has to be defined in time units such as minutes, hours, weeks, months or years.