Galarian Zigzagoon Community Day Guide for PvP

Galarian Zigzagoon will be making a special appearance in the wild this Community Day, bringing the chance to obtain optimal PvP IV's and Obstagoon's signature move, Obstruct. You can find more info on Galarian Zigzagoon Community Day at the Pokemon GO blog. Below are the leagues and IV spreads to look out for, and answers to frequently asked questions.
Special thanks to @SwgTips for the IV research! Check out his deep dive article on Obstagoon IV's for more on Obstagoon breakpoints and bulkpoints.
Overview
Date & Time
Event Bonus
Event Bonus
Exclusive Charged Move
League & IV Recommendations
Mega Evolve one of these Pokemon during Community Day to earn bonus catch candy!
How good is Obstagoon with Obstruct?
Obstagoon is already a top contender in Great and Ultra League. At worse, Obstruct will be a sidegrade to its existing move options. At best, Obstruct gives Obstagoon more dynamic play than before and allows it power through neutral matchups similar to Nidoqueen. Obstruct has two guaranteed stat effects at 40 energy (compared to Acid Spray at 45 energy and Feather Dance at 50 energy). Obstagoon can leverage this best in the Ultra League where it has more bulk to take advantage of the stat boosts.
Obstagoon is likely to continue using Night Slash as its primary Charged Move, with Obstruct as a secondary move option. Obstruct Obstagoon should shield early, throw Obstruct once or twice early in a matchup, and rely on Counter and Night Slash damage the rest of the way.