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How to Convert a Timestamp to a Readable Date/Time in Batch Script

Many systems store timestamps as a single long number, either a Unix Epoch (seconds since 1970-01-01) or a Windows FILETIME (100-nanosecond intervals since 1601-01-01). Converting these raw integers back into a human-readable "YYYY-MM-DD HH:MM:SS" format is essential for log analysis, auditing, and debugging.

In this guide, we will demonstrate how to convert a Unix Epoch timestamp to a readable date using PowerShell, and how to handle Windows FILETIME values.

Method 1: Unix Epoch to Readable Date (PowerShell Bridge)​

PowerShell provides the most reliable way to convert an Epoch timestamp.

Implementation Script​

@echo off
setlocal

:: Example Unix timestamp: 1703512800 (2023-12-25 14:00:00 UTC)
set "epoch=1703512800"

for /f "usebackq delims=" %%A in (`
    powershell -NoProfile -Command "[DateTimeOffset]::FromUnixTimeSeconds(%epoch%).LocalDateTime.ToString('yyyy-MM-dd HH:mm:ss')"
`) do set "readable=%%A"

echo.
echo ==========================================
echo EPOCH:    %epoch%
echo READABLE: %readable%
echo ==========================================
pause
UTC vs. Local Time

Unix Epoch timestamps are measured in UTC. The .LocalDateTime property automatically converts the result to your system's local timezone. To display the result in UTC instead, use .UtcDateTime:

powershell -NoProfile -Command "[DateTimeOffset]::FromUnixTimeSeconds(%epoch%).UtcDateTime.ToString('yyyy-MM-dd HH:mm:ss')"

Method 2: Windows FILETIME to Readable Date​

Windows sometimes stores dates as FILETIME (a 64-bit value). PowerShell can handle this conversion as well:

@echo off
setlocal

:: Example: FILETIME value
set "filetime=133479360000000000"

for /f "usebackq delims=" %%A in (`
    powershell -NoProfile -Command "[DateTime]::FromFileTime(%filetime%).ToString('yyyy-MM-dd HH:mm:ss')"
`) do set "readable=%%A"

echo.
echo FILETIME: %filetime%
echo READABLE: %readable%
pause
FILETIME Values Are 64-Bit

Windows FILETIME values are 64-bit integers that far exceed Batch's 32-bit limit. The value is passed to PowerShell as a string within the command and is never processed by Batch's set /a arithmetic. PowerShell's [DateTime]::FromFileTime() handles the full 64-bit range natively.

Method 3: WMIC DateTime to Readable Date (Pure Batch)​

The wmic command returns dates in a long format like 20231225140000.000000+060. You can slice this string into a readable format:

@echo off
setlocal enabledelayedexpansion

:: Get current datetime from WMIC
for /f "tokens=2 delims==" %%I in ('wmic os get localdatetime /value') do (
    set "dt=%%I"
)

:: Validate that dt is not empty
if not defined dt (
    echo [ERROR] Failed to retrieve system date.
    pause
    exit /b
)

:: Slice the string into readable format
set "readable=!dt:~0,4!-!dt:~4,2!-!dt:~6,2! !dt:~8,2!:!dt:~10,2!:!dt:~12,2!"

echo Formatted: !readable!
pause
WMIC Deprecation

wmic is deprecated in newer versions of Windows. As a future-proof alternative, you can retrieve the same formatted date string using PowerShell:

for /f "usebackq delims=" %%I in (`
    powershell -NoProfile -Command "Get-Date -Format 'yyyy-MM-dd HH:mm:ss'"
`) do set "readable=%%I"
WMIC Limitation

The WMIC method (Method 3) only converts the current system date and time. It cannot convert arbitrary timestamps. For converting stored or historical timestamps, use Method 1 (Epoch) or Method 2 (FILETIME).

Why Convert Timestamps?​

  1. Log Analysis: Server logs and event viewers often store events as Epoch timestamps. Converting them makes the data human-readable.
  2. Auditing: Checking when a file was last modified, a user last logged in, or a certificate was issued.
  3. Debugging: When comparing timestamps from different systems (Unix, Windows, databases), having them all in a readable format prevents confusion.

Important Considerations​

Batch-Friendly Epoch Conversion

If you need to convert many Epoch timestamps in a loop, you can batch them into a single PowerShell call to avoid the overhead of launching PowerShell repeatedly:

@echo off
setlocal enabledelayedexpansion

set "epoch1=1703512800"
set "epoch2=1703599200"
set "epoch3=1703685600"

for /f "usebackq delims=" %%R in (`
    powershell -NoProfile -Command ^
        "$epochs = @(%epoch1%, %epoch2%, %epoch3%); foreach ($e in $epochs) { [DateTimeOffset]::FromUnixTimeSeconds($e).LocalDateTime.ToString('yyyy-MM-dd HH:mm:ss') }"
`) do echo %%R
pause
Custom Output Formats

PowerShell's .ToString() method accepts any .NET date format string. Common alternatives include:

Format StringExample Output
'yyyy-MM-dd HH:mm:ss'2023-12-25 14:00:00
'dd/MM/yyyy'25/12/2023
'MMM dd, yyyy h:mm tt'Dec 25, 2023 2:00 PM
'yyyyMMdd_HHmmss'20231225_140000

Conclusion​

Converting raw timestamps to readable dates is a critical "translation" skill for any system administrator. By leveraging PowerShell's built-in date conversion methods, you can decode any timestamp format, Epoch, FILETIME, or WMIC, into a clear, standardized output. This capability is essential for log analysis, security auditing, and cross-system date synchronization.

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