This paper presents a formal specification method for real-time systems using metric temporal logic. Real-time systems are characterized by quantitative temporal properties, such as response time, frequency, and periodicity. The paper extends traditional temporal logic by introducing a distance function to measure time and analyze its restrictions. This allows for the expression of quantitative temporal properties in a formal way. The paper introduces metric temporal logic, which extends classical temporal logic by indexing temporal operators with parameters from a metric domain. This enables reasoning about both quantitative and qualitative properties. The paper shows how five typical real-time properties can be expressed in metric temporal logic, including response time, frequency, and periodicity. Examples are given to illustrate the application of metric temporal logic to real-time systems, including constructs such as time-out and wait/delay statements. The paper concludes that metric temporal logic provides a suitable framework for specifying real-time systems. Real-time systems are defined by their need to react to events in an autonomous environment in a timely manner. The interaction between the system and the environment is subject to quantitative temporal requirements, which can be classified into response time and frequency. The paper discusses the importance of formal specification methods for real-time systems, as they are increasingly used in critical applications such as nuclear power stations and flight control software. The paper also highlights the need for a formal method that can handle both qualitative and quantitative temporal properties. The proposed method, metric temporal logic, is based on extending classical temporal logic with a distance function and metric parameters. The paper concludes that metric temporal logic is a suitable formal method for specifying real-time systems.This paper presents a formal specification method for real-time systems using metric temporal logic. Real-time systems are characterized by quantitative temporal properties, such as response time, frequency, and periodicity. The paper extends traditional temporal logic by introducing a distance function to measure time and analyze its restrictions. This allows for the expression of quantitative temporal properties in a formal way. The paper introduces metric temporal logic, which extends classical temporal logic by indexing temporal operators with parameters from a metric domain. This enables reasoning about both quantitative and qualitative properties. The paper shows how five typical real-time properties can be expressed in metric temporal logic, including response time, frequency, and periodicity. Examples are given to illustrate the application of metric temporal logic to real-time systems, including constructs such as time-out and wait/delay statements. The paper concludes that metric temporal logic provides a suitable framework for specifying real-time systems. Real-time systems are defined by their need to react to events in an autonomous environment in a timely manner. The interaction between the system and the environment is subject to quantitative temporal requirements, which can be classified into response time and frequency. The paper discusses the importance of formal specification methods for real-time systems, as they are increasingly used in critical applications such as nuclear power stations and flight control software. The paper also highlights the need for a formal method that can handle both qualitative and quantitative temporal properties. The proposed method, metric temporal logic, is based on extending classical temporal logic with a distance function and metric parameters. The paper concludes that metric temporal logic is a suitable formal method for specifying real-time systems.