There were no clocks 1400 years ago, why do we care so much about exact timings of Adhan and prayer, etc time today?

This has been bugging for like a lot lately. back in the day, I mean 14 centuries ago, there were no clocks, etc, people would simply look at the sky and if they felt it was morning or noon or what ever, would say their prayers. But now a days, for example when fasting or breaking ones fast! we are meticulous about the seconds! and check if the time with extreme measures to see if its time or not!! IMHO this is too much! and we shouldnt realy care this much about time! Why do we care so much and since when has this been like this ? Update: Thanks everyone, some indicated some methods to get a better idea of time, but even with everything you say, looking at shadows, etc, you get a **relative time period** and nothing remotely close to precise timing with a clock down to minutes, and even seconds. More over, at nights(and dawn etc), there was no means to know what time it was, as it is also noted in Quran in one of verses. My point is, it obviously was never a big deal or important matter. The relativeness of time was always intended, since, if God wanted precise timing he would command his messenger to create a clock for his followers! so when he didn't, he must have never intended precise timing!