Banks sell funds from Monday to Friday. Selling funds starts at 9 o'clock every day and ends at 3 o'clock in the afternoon. I don't rest at noon and I still sell it! However, legal holidays do not sell funds!
If you really want to buy funds through the bank, I suggest you don't buy them directly at the bank counter, because the handling fee for buying them at the bank counter is very high, which is 1.5%!
But if you buy funds directly from the online system, the cost will be less than 1%! Every bank has launched online fund sales. You can apply for an online bank with a bank card, and you can buy it! As for network security, don't worry, as long as you buy it on your own computer, there will be no problem. Don't go to other people's computers for online banking!
Good luck!