History of Beat Time

Beat Time is a triumph with the in-game text: "Select the Beat Time modifier and complete an activity with grade B+ or higher." It has a single Progress objective.

How to complete

From the game text only: choose the Beat Time modifier before launching an activity that shows a loot or difficulty grade, and finish it with a grade of B+ or better. Modifiers that increase difficulty raise the grade, as in Portal activities.

Unconfirmed

I could not find a guide describing the Beat Time modifier, which activities offer it, what it does, or which season or seal the triumph belongs to. The TheGamer seasonal-challenge guides for Heresy and Echoes do not mention it. Treat everything beyond the game text as unverified.