wot_gorilla

Hello. I am designing a simple controller for a home-scale automated irrigation system. I am using some flip-flops and counters, so I will need a clock. I am familiar with digital circuits and I have done some VHDL, Verilog and FPGA programming, but I am a starter with the design of digital circuits using discrete elements. I have bought some parts, but I don't know what kind of clock I should use and where to find it. I looked on the Internet, and I found references to the following: IC8038 MAX038 ICL8038 XR2206 Are these what I'm looking for? How do you know what the frequency of these oscillators is? When you buy an oscillator, can you adjust its frequency? I am asking the question because I my counter will be counting minutes and perhaps even hours. My clock needs to be very slow, or otherwise I will be needing 10 or more 4-bit counters, which is ridiculous. Of course, if I can save some money, I'd like to. I'm not going to buy a 25 MHz clock if even a 1 Hz clock would do. Thanks in advance for your help.