How Accurate Were The Ancient's Water Clocks?

WEstern man has spent a lot of energy in devising ways to measure the flow of time. I have always wonderd about the sophistication of the water clocks constructed by the greeks and Romans… from what I understand, these machines could be quite eleaborate, displaying the time of day, the year, position of the earth relative to the sun, etc.
My question: have any modern reconstructions of these clocks been made? What sort of accuracy do they exhibit? And, did ancient Romans time their activities like we do? For example, would a Roman lawyer agree to meet his client in court at 6:00"o’clock"? Or were appointements a lot looser back then?

have any modern reconstructions of these clocks been made?

Modern? As in the last 100 years? Yes, they were still in use in Africa within the last 100 years … but you know how behind the times those Africans can be. Heck, they still had racial discrimination in South Africa as a matter of public policy until just recently.
What sort of accuracy do they exhibit?

Very poor … the water all evaporated ages ago.
And, did ancient Romans time their activities like we do? For example, would a Roman lawyer agree to meet his client in court at 6:00"o’clock"? Or were appointements a lot looser back then?

Appointments? Are you kidding?

Way more than you ever wanted to know about clepsydra.