Clock displays time of day. Time is invisible and exists virtually. Everyone of us has the same amount of time, no matter you’re rich or not. You can’t save up time for later use, borrow time from others, nor go back in time.
Everything in this universe is influenced by time – living individual getting aged, machines getting wear and tear, cutoff point in trading like stock, FX or bidding, project deadline, return of investment, interests etc. Time is also regarded as the 4th dimension.
In cyber world, time has its own unique characteristics. In central computing like mainframe, time signal orchestrates tasks coordination across components – data fetched from storage via data bus to processor for manipulation then sent to next destination. In decentralized computing with networked computers, time stamps the sequence of system events for trouble shooting and digital forensic.
It is therefore important to maintain the clock synchronization in the network. There are various considerations:
- Clock source: National lab, or GPS to the time server
- Each network zone has its own clock source or from the organization central infrastructure
- Frequency of the time sync with clock source
- Detection of time drift and acceptable tolerance
- Most important, what is the consequence of the time out of sync to the business and the community
- Affecting human safety
- Polluting the environment
- Invalidating high value transaction
- Unplanned outage of critical infrastructure
- and so forth…