One Chance a Day! or A Great Chance a Day! are a type of Special Stage. These stages can only be attempted once per day, after which the stage disappears. This means the maximum number of possible attempts is the duration of the event in days.
Jirachi is infamous for only appearing once a year for several days around Tanabata, a holiday in Japan associated with wish-making, as a reference to the Wish Pokémon.
Tornadus, Thundurus, and Landorus (Incarnate forms) are known for have increasing catchability as days pass. Their events usually last a week, so they will have an initial catchability on Tuesday when the event begins, and max potential catchability on Monday when the event ends.
As of the 3DS v1.5.7 and Mobile v1.12.3 updates (February 13, 2018), events are on rotation. Check the Current Events page for info on those events.
History[]
This table shows info about the Once a Day events held before the event rotation.
| Pokémon | Event Duration | Drops | Notes |
|---|---|---|---|
 Cosmoem
|
11/21/17 to 12/04/17 |  100% /  100% /  0.78125%
|
|
 Cosmog
|
11/07/17 to 11/20/17 | 100% / 25% / 6.25%
|
|
 Gengar (Spooky)
|
10/24/17 to 10/30/17 | 100% / 50% / 50%
|
|
 Mesprit
|
08/15/17 to 08/21/17 | 100% / 1000  50% /  12.5%
|
|
 Butterfree
|
07/18/17 to 07/31/17 | 100% /  25% /  25%
|
|
 Jirachi
|
07/05/17 to 07/07/17 | 100% / 25% / 25%
|
|
 Pikachu (Rayquaza Costume)
|
07/04/17 to 07/17/17 | 100% / 25% / 12.5%
|
|
| Cosmoem
|
05/09/17 to 05/22/17 | 100% / 25% / 6.25%
|
|
| Cosmog
|
04/25/17 to 05/08/17 | 100% / 25% / 25%
|
|
 Landorus (Incarnate)
|
04/11/17 to 04/17/17 | 100% / 12.5% /  6.25%
|
Costs 0  per attempt
|
 Thundurus (Incarnate)
|
04/04/17 to 04/10/17 | 100% / 12.5% / 6.25%
|
Costs 0 per attempt
|
 Tornadus (Incarnate)
|
03/28/17 to 04/03/17 | 100% / 12.5% / 6.25%
|
Costs 0 per attempt
|
 Pikachu (Lugia Costume)
|
03/14/17 to 03/27/17 | 100% / 25% / 12.5%
|
Costs 0 per attempt
|
 Pikachu (Ho-Oh Costume)
|
03/14/17 to 03/27/17 | 100% / 25% / 25%
|
Costs 0 per attempt
|
| Mesprit
|
02/28/17 to 03/13/17 | 100% / 25% / 12.5%
|
Costs 0 per attempt
|
 Pikachu (Enamored)
|
02/07/17 to 02/20/17 |    
(Please check the stage info for drop rates) |
|
 Pinsir
|
01/04/17 to 01/06/17 | 100% / 25% / 25%
|
|
| Jirachi
|
12/22/16 to 12/25/16 | 100% / 25% / 25%
|
Costs 0 per attempt
|
 Delibird (Holiday)
|
12/13/16 to 12/25/16 | 
(Please check the stage info for drop rates) |
Costs 0 per attempt
|
| Gengar (Spooky)
|
10/25/16 to 10/31/16 | ||
| Landorus (Incarnate)
|
10/18/16 to 10/24/16 | 100% / 12.5% / 6.25%
|
Costs 0 per attempt
|
| Thundurus (Incarnate)
|
10/04/16 to 10/10/16 | 100% / 12.5% / 6.25%
|
Costs 0 per attempt
|
| Thundurus (Incarnate)
|
08/09/16 to 08/15/16 | 100% / 12.5% / 6.25%
|
Costs 0 per attempt
|
| Jirachi
|
08/06/16 to 08/08/16 | ||
| Landorus (Incarnate)
|
07/26/16 to 08/01/16 | 100% / 12.5% / 6.25%
|
|
| Jirachi
|
07/06/16 to 07/08/16 | ||
| Tornadus (Incarnate)
|
06/21/16 to 06/27/16 | 100% / 12.5% / 6.25%
|
|
| Landorus (Incarnate)
|
06/07/16 to 06/13/16 | ||
| Pinsir
|
05/11/16 to 05/13/16 | ||
| Thundurus (Incarnate)
|
05/10/16 to 05/16/16 | ||
| Tornadus (Incarnate)
|
04/05/16 to 04/11/16 | ||
| Landorus (Incarnate)
|
03/15/16 to 03/21/16 | ||
| Pinsir
|
02/17/16 to 02/20/16 | ||
| Thundurus (Incarnate)
|
02/02/16 to 02/08/16 | ||
| Tornadus (Incarnate)
|
01/05/16 to 01/11/16 | ||
| Landorus (Incarnate)
|
12/08/15 to 12/14/15 | ||
| Thundurus (Incarnate)
|
12/01/15 to 12/07/15 | ||
| Tornadus (Incarnate)
|
11/09/15 to 11/15/15 | ||
| Pinsir
|
09/29/15 to 10/02/15 | ||
| Jirachi
|
07/06/15 to 07/09/15 | ||
| Pinsir
|
05/07/15 to 05/10/15 |