Juggernaut in Roblox Rivals appears to be a game mode/event that was added in early June 2025 , with multiple videos from June 5–9, 2025 showing players already using it in-game. I couldn’t verify a single official “Juggernaut Day” date from the available results, so the safest answer is that it seems to have launched as part of that June 2025 update rather than on one fixed annual day.

What the results suggest

  • The mode was being played publicly by June 5, 2025.
  • Several uploads from June 7–9, 2025 describe it as a “new Juggernaut gamemode” or “new update,” which supports that timing.
  • A later wiki listing shows Juggernaut as one of the current Rivals gamemodes, meaning it’s part of the game’s mode rotation/content now.

Practical takeaway

If you meant “when did Juggernaut come out?”, the best-supported answer is early June 2025. If you meant a scheduled return day or a special Juggernaut Day event, I couldn’t confirm an official date from the available public results.

Search-friendly answer

  • Release window: early June 2025
  • Official fixed day: not confirmed in the available sources
  • Current status: listed as a Rivals gamemode

TL;DR: Juggernaut seems to have arrived in Roblox Rivals in early June 2025 , but I couldn’t verify a specific official “Juggernaut Day”.