No starter

When I trie to start this car in the morning especially during cold waether, it will not start. It will not turn over nor make any sound, though all the lights including the radio will come on. I will priodically try to start this car through out the day. After probably two to three hours of trying, it will start just immediately without hesitation. Once it starts that day, it continue starting through out the day rgardless of how many times. Then it will do it again the next morning. I have taken it to mechanic several times for diadnosing. The ignition has been changed and charging and starting system have been thoroghly inspected and was told everything is fine.

The starter, battery, alternator are ok according to several mechanics shops including sears. This happens when the temperature is very cool to cold.

Once it starts on time a day, it will not do it again that day.
Please help me since I am running out of options.