Is it possible to send a delayed transaction using EOS? Say I want to send 5 EOS to someone after 24 hours has passed. How can one do this in EOS? Do I need a smart contract? And does my EOS get locked for that time frame?
Yes you can use cleos to do the delay send by adding the option:
--delay-sec [seconds to delay]
And no it does not lock up your eos, it will just fail when that time comes to send it.