Yes, this is quite practical with an Arduino. I suggest you start with the Arduino UNO, plus a relay shield and a RTC Real Time Clock. I don't know which keypad to recommend, but there's a lot out there that should work fairly easily.
The RTC modules are generally not sold as shields. It's such a small module that nobody wants to dedicate a whole shield to that function. Either buy a protoshield and solder it onto that or go for one of the more elaborate data-logging shields and ignore the extra functions for this project.
I personally have an aversion to shields. It seems like anything on a shield is at least $10 more expensive than just purchasing the component on a small PCB. Often the I/O pins one needs to use with a shield are not changeable so you can easily find yourself in a situation where have plenty of extra I/O pins but the two shields you want to use both use the same I/O pins. You need to bend a pin and add a jumper wire to use a different I/O pin.
I agree the Arduino could be used for this project just fine.
Start your project by learning how to program one part at a time then add another. Trying to program all at once will only add confusion. Save each working version as a separate program. This will allow you to return to a known good program when you completely stuff up adding another section to the code.
I personally have an aversion to shields. It seems like anything on a shield is at least $10 more expensive than just purchasing the component on a small PCB
DuaneDegn:
I personally have an aversion to shields. It seems like anything on a shield is at least $10 more expensive than just purchasing the component on a small PCB.
Well, if you don't need/ want shields, then you don't need a UNO.
A Nano - or Pro Mini if USB interface is not necessary other than for programming - will work nicely with stripboard. Or you can after prototyping, make a PCB on which the Nano/ Pro Mini mounts using pin headers (likely soldered), and even put components underneath.
