I have a 6000 BTU air conditioner window unit that says on it - input 620watts, 115volt-60htz 6 amp. I have an appliance timer that says - 125volt/60hz, 15amp general purpose/resistive@125VAC, 1250W Tungsten@125VAC. Will this timer be adequate for turning the ac on/off 4 times a day or do I need a more heavy duty timer.(doesnt an ac pull a lot of amps when the compressor cycles on and off)Thank you.

You need a timer that is rated for inductive loads, not just resistive loads. AC compressors draw 6-10 times the running current when starting, so the timer you have may not handle the starting current.