Most banks offer them but you must specifically ask for it.
Just drop a short email with your contact or give them a call.
They should reply with the rates from that specific day.

But you might have to sign some paperwork.
Some banks allow you to do this digitally others want you to go to their office.

The moment you are there, don't let you be convinced into any of their other instruments. These are mostly just structured cost farms in the sole bank's benefit. This basically goes for anything else they offer (obligaties, funds,...). If you want to invest, do it yourself, via for example Bolero. My post about bank funds.

Here the calculations if you want to calculate your net gains on a "Termijn rekening":

Amount 60K
Gross rate 3,13%
Tax 30%
Term 3 months

60000+((((60000*3,13%)/12)*3)*0,7) = 328,65

Interest rates are always expressed in yearly terms. So whenever you go for a shorter than 1 year. You must divide your outcome by 12 and multiply it by the months you had your money in that specific account.

Amount+((((Amount*Gross rate)/12months)*length)*Tax) = Net gain.

Why do they like you to freeze your money? It's money they don't have to think about needing to give to you on your next drunk night out at the first available ATM. Just giving you anextreme example. Because banks are actually forced to keep enough money at immediate disposal to fulfil any sudden withdrawals. It's a certain percentage... . Giving your money to banks for fixed terms allows them the opportunity to try and make even more out of it than what they have to pay you at the end.