PowerShell Unix Timestamp: Get-Date, DateTimeOffset & Ticks

Get the current Unix timestamp

# Seconds and milliseconds, explicitly UTC
[DateTimeOffset]::UtcNow.ToUnixTimeSeconds()       # 1767225600
[DateTimeOffset]::UtcNow.ToUnixTimeMilliseconds()  # 1767225600123

# One-liner via Get-Date (returns a [datetimeoffset] in PS 7)
(Get-Date).ToUnixTimeSeconds()

Convert a timestamp to a date

[DateTimeOffset]::FromUnixTimeSeconds(ts) returns a UTC DateTimeOffset. Display it with .ToString("u") (UTC) or convert to a named zone with [System.TimeZoneInfo]::ConvertTimeBySystemTimeZoneId. Avoid Get-Date -UFormat %s for precision work — it has historical quirks and returns a string.

$dto = [DateTimeOffset]::FromUnixTimeSeconds(1767225600)
$dto.ToString("yyyy-MM-dd HH:mm:ss zzz")            # 2026-01-01 00:00:00 +00:00

# Named zone (DST-aware on Windows via TimeZoneInfo)
$ist = [System.TimeZoneInfo]::ConvertTimeBySystemTimeZoneId($dto, "India Standard Time")
$ist.ToString("yyyy-MM-dd HH:mm:ss")                # 2026-01-01 05:30:00

Convert a date back to a timestamp

Build a [DateTimeOffset] with an explicit offset — never a bare [datetime], whose Kind is Unspecified and gets treated as local. Get-Date -Date '2026-01-01' -AsUTC is the clean PS 7 way to pin input to UTC.

# Explicit UTC offset — unambiguous
$dto = [DateTimeOffset]::new(2026, 1, 1, 0, 0, 0, [TimeSpan]::Zero)
$dto.ToUnixTimeSeconds()                             # 1767225600

# PS 7: Get-Date with -AsUTC
(Get-Date -Date '2026-01-01 00:00:00' -AsUTC).ToUnixTimeSeconds()

# ⚠ naive [datetime] is machine-local:
([datetime]'2026-01-01 00:00:00').ToUniversalTime()

Naive vs aware: [datetime] vs [datetimeoffset]

• [datetime] — naive. Kind may be Utc, Local, or Unspecified; the last is assumed local by most conversions.
• [datetimeoffset] — aware: wall-clock plus offset. All ToUnixTime* methods live here.
• TimeZoneInfo — the DST-aware path for named zones; ConvertTimeBySystemTimeZoneId handles transitions correctly.
• Rule: read with [DateTimeOffset]::UtcNow, write with explicit offsets, convert zones only for display.

Native precision: milliseconds (100ns ticks underneath)

.NET's [datetime]/[datetimeoffset] carry 100-nanosecond ticks, so UtcNow is millisecond-resolution on Windows. For the raw .NET value (100ns intervals since 0001-01-01), $dto.Ticks exposes it — that's the value the .NET ticks converter on this site decodes.

Common pitfalls

• [datetime] Kind=Unspecified — .ToUniversalTime() silently applies the machine offset.
• Get-Date -UFormat %s — string output, historically buggy across versions; use ToUnixTimeSeconds().
• Windows zone names — "India Standard Time" not "Asia/Kolkata"; on PowerShell 7 (.NET with ICU) IANA names also work.
• CSV/JSON round-trips — serializing naive datetimes loses the zone; emit ISO 8601 with offset (.ToString("o")).

Try it live

Check any value in the epoch converter, or copy the current timestamp from the PowerShell snippet tab on the homepage.