diff --git a/PKHeX.Core/Legality/Encounters/Data/Live/EncounterServerDate.cs b/PKHeX.Core/Legality/Encounters/Data/Live/EncounterServerDate.cs
index 277e167b0..e1f21f4c7 100644
--- a/PKHeX.Core/Legality/Encounters/Data/Live/EncounterServerDate.cs
+++ b/PKHeX.Core/Legality/Encounters/Data/Live/EncounterServerDate.cs
@@ -174,7 +174,8 @@ public static bool IsValidDateWC9(WC9 card, DateOnly obtained) => (WC9Gifts.TryG
         {0025, (new(2023, 04, 21), new(2023, 07, 01))}, // Pokémon Center Pikachu (Mini & Jumbo)
         {1003, (new(2023, 05, 29), new(2023, 08, 01))}, // Arceus and the Jewel of Life Distribution - Pokémon Store Tie-In Bronzong
         {1002, (new(2023, 05, 31), new(2023, 08, 01))}, // Arceus and the Jewel of Life Distribution Pichu
-        {0028, (new(2023, 06, 09), new(2023, 06, 12))}, // そらみつ's Bronzong
+        {0028, (new(2023, 06, 09), new(2023, 06, 12))}, // そらみつ's Bronzong (-1 start date tolerance for GMT-10 regions)
+        {1005, (new(2023, 06, 16), new(2023, 06, 20))}, // 정원석's Gastrodon (-1 start date tolerance for GMT-10 regions)
 
         {9021, HOME3_ML}, // Hidden Ability Sprigatito
         {9022, HOME3_ML}, // Hidden Ability Fuecoco