Does changing the date cause pokemon to appear?

[Sly Serperior]

I'm trying to get pansear and I know it's under the railroad bridge when it's raining. So I changed the date when it was raining but pansear didn't appear:(. 

[Zander]

If you change the date then obviously the rain might disappear. But try to set a date to when it's raining. Watch the TV to find out how the weather is like. And I think you have to at least enter and exit a building once

[Alistair]

Pansear doesn't require any badge to appear. The only requirement is a rainy weather. Try to set the weather to rainy using any means you have (changing the date might work but is bugged as mentioned above, or you could use a weather mod, there's a good one in the mods subsection).

Then enter any building and exit it to reset the overworld events. Pansear should be there for you to rescue.

[Brakk]

I dont know if there are any "date based" events, but changing time will certainly help you to trigger some of them and there are also Pokemon that do only appear at a certain daytime. 

[Sly Serperior]

So I decided to use the weather mod and he showed right up. Thanks everyone that responded to my question.