Evolution of Timekeeping in Windows


Staff member
Do you ever wonder how Windows computers keep the current time and how it is maintained on a day to day basis? Did you know that your computer needs to keep the correct time for you to access certain resources over the network?

Are you aware of regulations on time synchronization in certain industries in several regions across the globe and why that may be required? Did you know that some of the recent releases of Windows OS support sub-millisecond time synchronization accuracy?

Do you know what Precision Time Protocol is? You may have seen recent posts about various aspects of accurate timekeeping on the Windows Networking blog (e.g. 1, 2). Ever wonder what Windows Networking has anything to do with timekeeping?

Would you like to about the underlying technology that enables sub-millisecond time accuracy in Windows OS?

Read on to know more…

Accurate timekeeping has become a requirement for a variety of applications and Windows OS provides native support for accurate timekeeping and synchronization in a range of deployment topologies.

We are publishing a document (attached below) that paints an overall picture of timekeeping in operating systems, the various improvements to timekeeping in the Windows OS over the past several releases and how these improvements helped us realize improved time accuracy in the Windows OS. We also have some notes on where we may be headed next in this space. Fair warning that the document is a long read.

We hope that this informational document helps the readers understand the complexities of timekeeping, as well as our passion, commitment and successes with accurate timekeeping in the Windows OS.

The released features that are described in this document are covered in detail by our publications and blog posts and have been available to customers who sought to take advantage of high accuracy time keeping in Windows. We will publish details of any new time sync features/improvements in upcoming Windows releases when they are available for public use.

Written by: Sarath Madakasira

Source: Evolution of Timekeeping in Windows

My Computers

System One System Two

  • Operating System
    Windows 10 Pro 64-bit
    Intel i7-8700K 5 GHz
    ASUS ROG Maximus XI Formula Z390
    16 GB (8GBx2) G.SKILL TridentZ DDR4 3200 MHz
    Graphics Card(s)
    Sound Card
    Integrated Digital Audio (S/PDIF)
    Monitor(s) Displays
    3 x 27" Asus VE278Q
    Screen Resolution
    Hard Drives
    1TB Samsung 970 EVO Plus M.2,
    250GB Samsung 960 EVO M.2,
    6TB WD Black WD6001FZWX
    8TB WD MyCloudEX2Ultra NAS
    Seasonic Prime Titanium 850W
    Thermaltake Core P3
    Corsair Hydro H115i
    Logitech MX Master
    Logitech wireless K800
    Internet Speed
    1 Gb/s Download and 35 Mb/s Upload
    Other Info
    Logitech Z625 speaker system,
    Logitech BRIO 4K Pro webcam,
    HP Color LaserJet Pro MFP M477fdn,
    Linksys EA9500 router,
    Arris SB8200 cable modem,
    Lumia 1520 phone
  • Operating System
    Windows 10 Pro
    HP Envy Y0F94AV
    i7-7500U @ 2.70 GHz
    16 GB DDR4-2133
    Graphics card(s)
    NVIDIA GeForce 940MX
    Sound Card
    Conexant ISST Audio
    Monitor(s) Displays
    17.3" UHD IPS touch
    Screen Resolution
    3480 x 2160
    Hard Drives
    512 GB M.2 SSD