Personal NTP Server — run your own time server on your Windows PC, and know exactly how accurate it is. Every device on your network needs the right time. Cameras stamp their footage with it, servers validate certificates against it, and door controllers, NAS boxes and IoT sensors quietly break when they drift. Personal NTP Server turns your PC into a standards-compliant NTP time source for your whole local network — no cloud service, no subscription, no internet connection required. What sets it apart is honesty. Most simple time servers claim to be accurate whether they are or not. This one measures itself against a real reference and tells you the truth, in plain language, on the main screen. ★ ONE-CLICK SERVER Pick a port, press Start, and every device on your network can synchronise to your PC. A live indicator shows whether the server is running, which port it is listening on, and how many requests it has answered. ★ TRUE TIME, HONESTLY REPORTED Point the app at an upstream source such as time.google.com or pool.ntp.org. It measures the difference using the standard four-timestamp NTP exchange, then serves corrected time and advertises itself at the correct stratum — one level below whatever it follows. With no upstream source configured, it does not pretend. It advertises stratum 16 and the unsynchronised flag, exactly as the standard requires, so clients know to treat it as a last resort rather than a trusted reference. The main screen always says which of the two it is doing, and why. ★ YOUR WINDOWS CLOCK IS NEVER CHANGED The measured correction is applied only to the time being served. Your PC's own clock, and every application relying on it, is left completely untouched. No administrator prompts, nothing on your machine to undo later. ★ BUILT-IN NTP QUERY TOOL Test any NTP server — public or your own — and get a full breakdown rather than a single number: server time in UTC, the same instant in your local timezone, a true clock offset, the network round-trip delay, stratum, reference ID, protocol version and leap-second indicator. It also understands the failure cases. A server that is rate-limiting you, one that has not synchronised itself, or something that is not an NTP server at all — each is reported clearly instead of silently returning a nonsense timestamp. ★ QUERY HISTORY Every query is recorded with its server, UTC time, offset, delay, stratum and reference ID. Compare several sources at a glance and watch drift build up over time. ★ PERFECT FOR • Home labs and test networks with no internet access • Air-gapped and isolated environments • Security cameras and NVRs that need consistent timestamps • IoT sensors, controllers and embedded devices • Verifying an NTP client's configuration before deployment ★ PRIVATE BY DESIGN Runs entirely on your machine. No cloud, no telemetry, no account, no data leaving your network. It is powered by a compact native C engine with no external dependencies, so it uses very little memory and starts instantly. ★ TECHNICAL DETAILS • NTP version 4, RFC 5905 compatible • Correct leap indicator, stratum and reference ID handling • Kiss-o'-Death detection and reporting • Configurable UDP port, and configurable upstream poll interval • Handles concurrent clients • Live statistics and sync state, refreshed every two seconds • 64-bit timestamps with era-rollover handling Your network, your time source, your clock.