Condition green was the standard, peacetime status of all Starfleet vessels. Crewmen go about their regular duties, while off-duty personnel can engage in a range of activities such as holodeck time, fraternizing or completing research for example.
The mandatory bridge crew of a starship on condition greeen consisted of a Command officer, a Flight controller, a Science officer or an Operations manager. In cases were the Federation was in a "state of emergency" it was requied to have a weapons or tactical officer. Though some Captains preferred to keep a full bridge compliment when on condition green.
While on this condition the navigational deflector are up, forty percent of the ship's weapons are on stand-by status and expected to power up in two minutes. A shuttlecraft would remain ready for launch in five minutes in the shuttlebay. Also the operations manager or First officer is required to run level 4 diagnostic scans of the ship's primary systems. (Decipher module: Starfleet Operations Manual)