“A judge should address an application for relief from sanctions in three stages. The first stage is to identify and assess the seriousness and significance of the “failure to comply with any rule, practice direction or court order” which engages rule 3.9(1). If the breach is neither serious nor significant, the court is unlikely to need to spend much time on the second and third stages. The second stage is to consider why the default occurred. The third stage is to evaluate “all the circumstances of the case, so as to enable [the court] to deal justly with the application including [factors (a) and (b)]”.”
“… unless the court orders otherwise, the time for doing the act in question may be extended by prior written agreement of the parties for up to a maximum of 28 days, provided always that any such extension does not put at risk any hearing date.”