★What does time mean？

Time is the performance of the continuity and sequence of material movement and change, including the concepts of time and period. Time is a parameter used by human beings to describe the process of material movement or event occurrence(时间是物质运动、变化持续性、顺序性的表现，包含时刻和时段两个概念。时间是人类用以描述物质运动过程或事件发生过程的一个参数)

The above description should be a physical concept. If we want to pursue the essence, it belongs to the philosophical category. We need to ponder on time.(上述描述应为物理概念。如果我们要追求本质，那么它属于哲学范畴，我们需要沉思。)

视频：Time is free, but priceless（时间是无价的）

视频：Use time wisely， you can accomplish anything 

（善用时间，你能获得任何成就）

Time is an indispensable（不可或缺的） resource for any project. Its significance（意义） for project management is reflected in two aspects: Every project must face a final delivery date（最后的交付日期）, which constitutes one of the three constraints（约束） of the project. All management activities are inevitably carried out around the time coordinate（时间坐标）, which provides an important quantitative index（量化指标） and ruler for the project. Project time management is the most characteristic part of project management knowledge system. Many contents of quality, cost, procurement, human resources and risk management overlap（重叠） with Business Administration（工商管理） ,but only time management is the unique content of project management.

★what does schedule mean?  (noun ;  verb  名词或者动词）

Scueduling（工作计划，日程安排） is a scientific and artistic management activity around time and other resources. 

视频：Scheduling a business meeting

▶In project management, a schedule is the tool most commonly used to plan the project step by step. By systematically analyzing each activity and its relationship to the ones that come before and after it, the project manager can build the project on paper before committing resources to it.

▶Schedules are essential to the successful execution（执行） of any complex project. They are not unique to construction but are found in many industries, including business, manufacturing, and publishing. Whenever people, equipment, materials, and organizations are brought together and directed toward a common goal, they need a common tool that will identify how resources are going to be committed.

▶Construction schedules are considered acceptable in court when arguments occur over project completion or delivery dates or in the formal coordination of project participants. Conflicts can occur over many issues during the course of a construction project. Design changes, poor weather conditions, labor actions, and miscommunication of deliveries, are all a common basis for conflicts. If the parties involved are unable to work out their differences through negotiation or arbitration, the alternative is to use the court system. At the court level, judgments that involve time and project coordination are made using a network schedule.

▶Schedules establish the start, duration（持续时间）, and completion dates of a project or a task. They let people and organizations know in advance when to expect a certain action to take place. Contractors, and suppliers, to stay profitable, have many jobs that must be organized and planned. The start and completion date of a particular job is essential information because it allows them to determine whether or not the job can be accomplished in the context of their other work. Knowing precisely how long an activity will take also has substantial cost implications. (for example: Scheduled start dates determine when goods and services need to be brought to the job site, when a workforce needs to be mobilized, and when equipment rentals begin. this date is critical to the accurate pricing of the project. a delay in the start of the project could significantly affect the cost of a material and the rate at which labor can be bought.)