Every trading bot lives or dies by its clock. Exchanges stamp events in their own time base, your machine stamps them locally, and the gap between the two is a silent source of bugs. Clock drift is the difference between your system time and true UTC; even 200 ms of drift can make a fill look like it arrived before the order that caused it.

Production bots use NTP (Network Time Protocol) or PTP (Precision Time Protocol) to keep drift under a few milliseconds. Binance, for example, rejects signed requests whose timestamp is more than 1000 ms from server time — a hard failure mode caused purely by clock skew.

Always store timestamps in UTC, never local time.
Record both event time (exchange) and ingest time (your process).
Log the delta — it is your earliest warning of network trouble.

Source	Typical drift	Fix
Laptop, no NTP	1–30 s/day	Enable OS NTP
Cloud VM, NTP on	1–50 ms	chrony + monitoring
Colocated, PTP	< 1 ms	Hardware timestamping