Remember? He doesn't have an oscilloscope!
Let's hope that the value of R1 is small with respect to R2. If not, for now, make the value of R1 1K ohm and the value of R2 somewhere around 47K ohms. The output should then be close to a square wave. If the value of R1 is already small compared to that of R2, leave the circuit as is.
Connect a 150 ohm resistor in series with the anode of a common LED. With your 555 circuit running, ground the cathode (flat side) of the LED and connect the other end of the 150 ohm resistor to the +5v supply and note the LED brightness. Now connect the resistor to the output (pin 3) of the 555. If the 555 is working properly, the LED will still glow, but the brightness should be dimmer.
When folks see a digital clock, they tend to expect some accuracy. By trading out the original 60 Hz source (it was from the line voltage, I'm sure) and the other two counters with the 555, you've seriously affected the accuracy of the clock and you'll be chasing the time all over the place. You'll notice error creeping in each day if not each hour.
The orignal 60 Hz was probably a sample taken fron the secondary of the power transformer. If you're using a wall wart or other power supply, you may not have a secondary from which to tap. So, you're stuck with the 555 at this point. But if you want accuracy without the line frequency sample, then you could make a simple crystal oscillator driving the appropriate counter chain to give you your 1 pps output to drive the seconds counter.
Dean