Hello and welcome. Response time to emails varies on the site, just as it does in our own lives. Some respond within minutes, whereas others take days. Those who take longer to respond sometimes miss out on opportunities.
If you would like feedback on your listing, given it’s your first one, I suggest you add it to your forum profile. That way people can perhaps give you feedback that might be helpful.
As for timing and weather, the variety of sitters and their likes and dislikes is endless. I don’t think you should be disheartened by those factors. During the pandemic, there are any number of reasons why responses and applications might be slow. One hint I’ll share is not to accept someone you’re not comfortable with just because no one else has applied. Make sure it’s a good fit for everyone involved, as it’s so important.
I hope all goes well for you.