Count days between calendar dates.

PowerShell: Parse an unambiguous format before subtracting date values.

$ErrorActionPreference = 'Stop'
Set-StrictMode -Version Latest
$culture = [Globalization.CultureInfo]::InvariantCulture
$start = [datetime]::ParseExact('2026-02-01','yyyy-MM-dd',$culture)
$end = [datetime]::ParseExact('2026-03-01','yyyy-MM-dd',$culture)
($end-$start).Days

Expected output EXAMPLE

Details

Requires PowerShell 7. Save as snippet.ps1 and run pwsh -NoProfile -File snippet.ps1. Tested on Linux; these examples use portable paths and cmdlets. Parse an unambiguous format before subtracting date values.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · 2026-11-02 18:23:13 UTC · PowerShell 7.6.6 · powershell 7.6.6-1.deb

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Snippet process uid 65534 with a read-only root filesystem and temporary working files. Networking disabled. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel: x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale: uid=65534, gid=65534 (unprivileged process) / C.UTF-8
Interpreter invocation: pwsh -NoLogo -NoProfile -NonInteractive -File snippet.ps1
Container image ID: sha256:ec91410a8f6ec3e985830b5e3a0560306d36f8c1c5ccd91a6699abe707123fa3
Code SHA-256: 61ce74a8b8ff7f522e7d695e68430997edb7bb140e796683d0b11905e7fe80ce
Dependencies: powershell 7.6.6-1.deb

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.