Where is the clock (CLK) in Quartus schematic entry?

I'm new to the quartus design software and have been entering small designs (so far) in the integrated *.bdf schematic editor (you know, where you wire simple gates together).

The design I'm working on right now requires a clock signal,which will run at something like 0.5-10 Hz. The design will be downloaded to a DE2-115 board.

So far as I can tell, the "Symbol Tool" library in the block diagram editor doesn't contain a variable speed (or any other) clock. Is the normal solution to build a clock as a verilog module and then import it?

Any suggestions would be appreciated!