I just want to ask about working for 12hrs in...

In case you are inquiring about your employer did not pay your overtime pay, find the following information:
The Kuwaiti Labor Law obliges the employer to pay extra wages to the worker if the worker does overtime work exceeding the usual work hours.
If the employer refuses to pay the overtime wage, the worker can file a complaint against the employer.
Find the Kuwaiti Labor Law replying your inquiry:
Article (66)
Without prejudice to Articles (21) and (64) of this Law, the employer may, by means of a written order, have workers work overtime if the necessity arises for the purpose of preventing a dangerous accident, repairing damages arising from such accident, avoiding a loss or facing an unusual work load. The overtime work should not exceed two hours a day, a maximum of 180 hours a year, three days a week or 90 days a year. The worker shall have the right to prove by any means that the employer required him to perform additional works for an additional period of time. The worker shall also be entitled to a
25 percent increase over his original remuneration for the period of overtime. This remuneration shall be in conformity with Article (56) of this Law. The employer shall keep a special record for overtime work showing the dates, number of hours worked and remunerations paid in consideration of the additional work assigned to the worker.