Network Delay
-
Device time diagnostic
Clock Drift Test
Compare your device clock with network-calibrated atomic time. Use the offset, delay, and accuracy estimate to decide whether your computer needs a time sync check.
Device Clock Offset
-
Calibrating○ Syncing
Measuring network delay and comparing your device clock with calibrated time.
Estimated Accuracy
-
Last Sync
-
What It Means
Positive offset means calibrated time is ahead of your device clock. Negative offset means your device clock is ahead.
Live Comparison
- Device time
- -
- Atomic time
- -
Diagnostic Report
Copy this report when troubleshooting login, certificate, logging, or distributed-system time issues.
Time.ms Clock Drift Report
Under 100 ms
Usually excellent for browser, logging, and most user-facing workflows.
Over 1 second
Worth checking automatic time sync, VPN behavior, VM host time, or system time settings.
Over 1 minute
Can break authentication, certificates, scheduled jobs, and audit trails.
Related Time Tools
After checking drift, convert timestamps, inspect UTC, or use the NTP setup guide to correct system time.
Exact Time Now
Live atomic time with milliseconds, UTC, Unix time, network delay, and device offset.
Unix Timestamp
Convert epoch seconds or milliseconds to local time, UTC, ISO 8601, and back.
UTC Time
Check current UTC with milliseconds and convert local date-time values to UTC.
ISO 8601
Create, parse, and convert ISO timestamps for logs, APIs, and databases.
NTP Setup
Configure your computer or server to keep system time synchronized.
Accuracy Guide
Understand RTT, estimated accuracy, device offset, fallback behavior, and privacy boundaries.
Clock Drift FAQ
What is clock drift?
Clock drift is the difference between your device clock and a more reliable time reference.
What offset is acceptable?
A few hundred milliseconds is usually fine for browsing, while authentication and distributed systems often need tighter alignment.
How does this test estimate accuracy?
Time.ms measures network round-trip delay and uses half that delay plus a small browser timing allowance.