Pokémon Black and White have many reoccuring events that happen on a daily or weekly basis. Below is a list of all of them, separated by location time and location.
Daily
Pokémon Swarm
Each day at midnight after obtaining the national Pokédex a new location and Pokémon will be picked to swarm. Like in previous games swarms are an opportunity for rare Pokémon to show up. The Pokémon that show up in these swarms are not found in the Unova Pokédex and the swarms are the only way to obtain these Pokémon outside of trading or PokéTransfer.
Nacrene City
Free Furniture
Every day a house in Nacrene City east of the Pokémon Centre will offer you a new piece of furniture which you can add to your house in the Dream World.
Star Piece
Just east of Nacrene City, south of the entrance to Pinwheel Forest is a rock which you can hit with a Fighting type Pokémon for a Star Piece.
Castelia City
Pokémon Massage
Head to the alley east of the Pokémon Centre and go in the building on the left. Speak to the woman in the lobby and she will give one of your Pokémon a massage, which will increase their happiness.
GameFreak Battle
You must have obtained the National Pokédex for this to happen. Head into the building opposite the place you get a massage and head up the lift. Speak to one of the GameFreak employees and they will challenge you to a daily Pokémon battle. Their Pokémon are a round lv. 75 so be prepared.
Royal Unova
You can only access the Royal Unova after obtaining the National Pokédex. Each evening the Royal Unova will take off from Castelia port and make a round trip. It costs 1,000 to get on this boat and has a maximum of 7 trainers to fight. You are on a time limit, however, and not every cabin contains a person willing to fight. Use the clues provided by the cabin crew to maximise your battle count here.
Nacrene City
Stadium Battles
There are two stadiums in Nacrene City, one large and one small. The two stadiums are not always accessible but they each change sports twice a day and the fans/athletes will battle you with mid level 60 Pokémon. Sometimes when you win they will give you items.
Ferris Wheel
After obtaining the National Pokédex a trainer will be at the base of the ferris wheel every day and will ask to ride it with you. Before you do though, they will challenge you to a Pokémon battle.
Driftveil City
Heart Scale
One of the houses in Driftveil City contains a woman who will ask to see a specific Pokémon with a specific move. If you show her what she requests she will give you a Heart Scale.
Twist Mountain
Free Fossil
Head inside Twist Mountain and speak to one of the NPCs that look like they come from the Cold Storage in Driftveil City. They will give you a fossil which will contain one of the fossil Pokémon not from Unova.
Tubeline Bridge
Weather Rocks
At the western entrance to Tubeline Bridge is a Parasol Lady that will give you a weather rock depending on the time of day you come see her. You can only obtain one rock per day, but there is no limit on how many rocks you can obtain.
| Rock | Name | Time Obtainable | Makes the weather condition of this move last longer in battle |
|---|---|---|---|
 |
Damp Rock | 05:00-09:59 | Rain Dance |
 |
Heat Rock | 10:00-16:59 | Sunny Day |
 |
Smooth Rock | 17:00-19:59 | Sandstorm |
 |
Hail Rock | 20:00-04:59 | Sunny Day |
Opelucid City
Free Props
In the most western house in Opelucid City contains a man that will give you a free prop every day, although he will only give out a maximum of 4 props. His props are unique so he is the only place you can find them. 100 props are required to obtain a star on your Trainer Card.
Triple/Rotation Battles
One of the northern houses contains trainers who will battle you. In Pokémon Black they will challenge you to Rotation Battles and in Pokémon White they will challenge you to Triple Battles.
Village Bridge
Lum Berry At the foot of the eastern side of Village Bridge lies a small trailer, which is where Village Sandwiches are served. You can’t buy Village Sandwiches yourself, but you can get a job serving them to customers. This involves a small mini-game of taking and remembering orders. Get it right and you’ll receive a Lum Berry as a reward. Free Dive Ball A fisherman at Village Bridge will ask for a different fish Pokémon each day. If you show him what he requests, he’ll give you a Dive Ball.
Undella Town
Cynthia Every day in Spring Cynthia can be battled in the eastern most house in Undella Town. She is incredibly strong with Pokémon in the mid level 70’s so be careful! Undella Villa At the very west of Undella Town sits a massive villa owned by a multi-billionaire. You may battle a new trainer here every day for 6 days, though they cannot be rebattled.
Route 13
Treasure Hunter On Route 13 lies a Treasure Hunter dressed up as a man in a Black Suit. Speak to him each day and he will offer you a free item. The item will either be a flute, an item to let Pokémon hold to evolve them or an item meant for a specific Pokémon.
Black City/White Forest
Free Items / Trainer Battles
Depending on the version you have, you will either be able to battle trainers or collect new items daily.
Marvellous Bridge
Free Bigmushroom
You must first have spoken to the woman with four Patrats in Village Bridge for this to happen. If you have, you will find her and her four Patrats standing in the middle of the bridge. Speak to them each day for a chance to play a small mini-game and win a Bigmushroom.
Weekly
Battle Bianca
Having beaten the Elite Four you will find Bianca in Professor Juniper’s laboratory. Speak to her and from then on she can be battled every subsequent Saturday evening here.
Dreamyard
After beating the Elite Four you can access the Dreamyard. Each Friday a Musharna that has the Telepathy ability will spawn here.
Casteliacone
Every Tuesday outside of winter you may purchase a Casteliacone from the vendor in Castelia City. They cost 100 and essentially act like Full Heals.
Anville Town
Lost Property
The conductor in the south eastern house in Anville Town will give you multiples of a free lost item each week. The items are random, so check back each week.
Item Trading
On the weekends you can find large crowds here who will offer various item trades.