By way of derogation from article R. 5122-2, the employer has a period of thirty days from the date on which the employees are placed on partial activity to send his request by any means giving a certain date of receipt:
1° In the event of suspension of activity due to an accident or bad weather as provided for in 3° of article R. 5122-1;
2° In the event of exceptional circumstances as provided for in 5° of article R. 5122-1.