What is the time limit for filing an appeal to the Appellate Tribunal?

Section 26 Appeal to Appellate Tribunal: (3) Every appeal preferred under subsection (1) or sub-section (2) shall be filed within a period of forty-five days from the date on which a copy of the order made by the Adjudicating Authority or Director is received and it shall be in such form and be accompanied by such fee as may be prescribed: Provided that the Appellate Tribunal may, after giving an opportunity of being heard, entertain an appeal after the expiry of the said period of forty-five days if it is satisfied that there was sufficient cause for not filing it within that period.