What is the legal test for appellate review of a judge's decision not to grant an extension of time to a hearing?

The decision to allow or refuse an extension of time is discretionary in nature. The test for appellate review of the exercise of judicial discretion is whether the judge at first instance has given sufficient weight to all relevant considerations. See Reza v. Canada, 1994 CanLII 91 (SCC), [1994] 2 S.C.R. 394 at 404.

In Grewal v. Minister of Employment and Immigration, [1985] 2 F.C. 263, Thurlow C.J. identified considerations that may be relevant in an application to extend time. These considerations include: 1. whether the applicant intended to bring the judicial review within the period allowed for bringing the application and whether that intention was continuous thereafter; 2. the length of the period of the extension; 3. prejudice to the opposing party; 4. the explanation for the delay; and 5. whether there is an arguable case for quashing the order the applicant wishes to challenge on judicial review.