New standard for time and date in railways allow better system integration
Using the same time scale and staying close to a reference clock is crucial for digital systems.
It helps with communicating, coordinating actions, and keeping data consistent. It also supports encryption and cybersecurity.
There are many sources of time and date information for systems, but they are not always aligned. For example, Coordinated Universal Time (UTC) is 37 seconds behind atomic clock time and 18 seconds behind GPS time.
If we do not know this or cannot tell which time source a system uses, comparing timestamps from different systems can be confusing. This might hide the sequence of events, cause confusion, or make events appear falsely aligned. In turn, this can hamper incident and failure investigations.
The new standard encourages using Coordinated Universal Time (UTC) more widely.
It also promotes consistent formatting of time and date data and effective documentation of clock capabilities.
The standard includes:
- definitions to describe time attributes and how to measure them
- guidance on the different time and date sources and their differences
- description of factors that may affect clock time and date, including cybersecurity
- a common method for describing clock accuracy, resolution, drift, and synchronisation
- requirements for formatting and presenting time and date values.
By providing guidance on time and how to translate between time sources, accident and failure investigations can be quicker.
This is important when comparing timestamped data from different sources to understand the sequence of actions leading to an event.
This standard saves investigators’ time. Faster investigations find causes and defects sooner, allowing for earlier actions and risk mitigations to prevent future incidents.
Having a common method to describe clock accuracy, resolution, drift, and synchronisation helps in designing or specifying a system. This makes data aggregation and interrogation easier.
Also, detailing cybersecurity vulnerabilities and their mitigations for different time sources can protect railway systems. It can also inform those using systems about potential risks and hazards.