Please follow the guidelines specified in the Bulbapedia manual of style.

Timeline of Ruby and Sapphire's 80-day challenge

The fourth chapter of Pokémon Special is the story of Ruby and Sapphire, their 80-day challenge, and the crisis caused by Team Aqua and Team Magma unleashing Kyogre and Groudon.

Spoiler warning: Major plot or ending details may follow.

Volume 15

Days left	Date	Ruby		Sapphire
80	July 2	Littleroot Town	Ruby's birthday. Runs away from home aiming to conquer all the Pokémon Contests.	Littleroot Town	Encounter with Ruby; makes the 80-day challenge.
79	July 3	Oldale Town	Arrival at Oldale. Gives Mudkip the nickname Zuzu.	Littleroot Town	Sets out on journey aiming to conquer all the Gyms.
78	July 4	Petalburg City	Encounter with Wally. Near miss with his father, Norman.	On the move
77	July 5	Petalburg City	Captures a Pokémon with Wally; falls into a river and gets carried away.	Petalburg Woods	Battle with Team Aqua. Receives the letter from President Stone.
76	July 6	Over the seas	Unconscious. Rescued by Mr. Briney.	Rustboro City	Battle with Roxanne; obtains the Stone Badge.

Days left	Date	Ruby		Sapphire
75	July 7	Over the seas	Awakens. Battles against Crawdaunt aboard the boat.	On the move over the seas on Wailord
74	July 8	Towards Dewford Town
73	July 9
72	July 10
71	July 11
70	July 12	Dewford Town	Battles together with Steven. Meets Sapphire.	Dewford Town	Battle with Brawly; obtains the Knuckle Badge.
69	July 13	On the move over the seas on Sapphire's Wailord
68	July 14	Abandoned Ship	Battle together against Team Magma with Plusle and Minun.
67	July 15	On the move on Sea Route 109 using Sapphire's Wailord
66	July 16
65	July 17
64	July 18
63	July 19
62	July 20
61	July 21

Days left	Date	Ruby		Sapphire
60	July 22	Slateport City	Captured by Mack; escapes from the submarine by escape pod.	Route 110	Parts ways with Ruby.
59	July 23	Adrift		On the move on Route 110
58	July 24			On the move on Route 110
57	July 25			Mauville City	Receives the Dynamo Badge from Wattson.
56	July 26	Route 118	Fishes up Mimi. Battle with his father, Norman.	On the move on Route 111
55	July 27	Weather Institute	After an all-night battle with Norman, picked up by Gabby and Ty.	On the move on Route 111
54	July 28	On the move in Gabby and Ty's van		On the move on Mt. Chimney
53	July 29
52	July 30
51	July 31
50	August 1

Days left	Date	Ruby		Sapphire
49	August 2	On the move in Gabby and Ty's van		Mt. Chimney	Battle against Team Aqua. Obtains the Heat Badge from Flannery.
48	August 3			On the move through the Jagged Pass
47	August 4
46	August 5
45	August 6
44	August 7
43	August 8
42	August 9
41	August 10
40	August 11
39	August 12	Arrival at Verdanturf Town
38	August 13	Verdanturf Town	Enters a Normal Rank Pokémon Contest. Confrontation with Courtney; escapes.
37	August 14	On the move in Gabby and Ty's van
36	August 15
35	August 16
34	August 17
33	August 18
32	August 19
31	August 20	Fallarbor Town	Enters a Super Rank Pokémon Contest; becomes Wallace's apprentice.

Days left	Date	Ruby		Sapphire
30	August 21	Fortree City	Refuses to join Sapphire and the Gym Leaders.	Fortree City	Meets the Gym Leaders. Becomes enraged by Ruby.
29	August 22	Escapes to Slateport City			Battle with Winona; obtains the Feather Badge.
28	August 23	Slateport City	Enters a Hyper Rank Pokémon Contest; loses Mimi.		Witnesses Kyogre and Groudon.
27	August 24	Ruby decides to join Sapphire and the Gym Leaders.		Goes to the Seafloor Cavern together with Ruby.

Days left	Date	Ruby		Sapphire
26	August 25	Seafloor Cavern	Battle against Kyogre and Groudon.

Days left	Date	Ruby		Sapphire
25	August 26	Sootopolis City	Grand Meteor discharge; engulfed in the explosion.
24	August 25	Unconscious on Mirage Island (The flow of time on Mirage Island is abnormal.)
...
4	September 16	Mirage Island	Awakens. Intensive training with Juan, Tate, and Liza.	Mirage Island	Receives the Rain Badge and Mind Badge at the end of the training.

Days left	Date	Ruby		Sapphire
3	September 17	Sootopolis City	The final battle with Kyogre and Groudon.	Sootopolis City	Chases Ruby in Wallace's car.
2	September 18	Sootopolis City	The final battle with Archie and Maxie.
1	September 19	One Contest rank remaining: the Master Rank.		One Gym badge remaining: the Balance Badge.
0	September 20	Sapphire's secret base	All Contest ribbons obtained.	Sapphire's secret base	Sapphire's birthday. All Gym badges obtained.