Monastic Tradition: Way of the Tilting Hourglass

From publisher blurb:

World-weary travelers will sometimes be shocked upon returning to a monastery they’d previously visited years later, only to find that its insular community has not changed one iota over the years. With practiced meditation, monks following the Way of the Tilting Hourglass develop the ability to regulate the flow of time around them, granting them uncanny speed in battle and slowing their foes to a glacial crawl.

Expanding upon the mechanics of the 5E Monk class, this PDF allows you to create monks who have developed a mastery over their personal sense of time, allowing them to speed themselves up or slow enemies in battle.