The deadline for making a complaint is one year.

The Act respecting collective agreement decrees provides that any civil action arising out of the decree is prescribed from the due date by one year.

In other words, the Parity Committee can claim salary deficiencies from you employer up to 1 year after the date of the object for which there is a deficiency.

For example, your employer forgot to pay you for the Remembrance day holiday in 2022, the holiday of November 11th, 2022. You have until November 11th, 2023 to file a complaint with the Parity Committee to this effect.