Add calendar days with GNU date.
Linux Commands: Anchor date arithmetic at a fixed UTC date to avoid local daylight-saving ambiguity.
TZ=UTC date -d '2026-01-30 +3 days' '+%F'Expected output EXAMPLE
2026-02-02
Details
Run in Bash on GNU/Linux in a scratch directory. Tested with the GNU utilities supplied by Ubuntu. Anchor date arithmetic at a fixed UTC date to avoid local daylight-saving ambiguity.
Tested on Ubuntu 24.04.5 LTS · · GNU bash, version 5.2.21(1)-release (x86_64-pc-linux-gnu) · bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
Test inputs, results and environment
The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. 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) / C.UTF-8
- Interpreter invocation
bash -euo pipefail -c <published code>- Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd- Code SHA-256
986bb2aa877f8618e86cb731dc02fd8cb0cddda662a13882f41c229fc489653a- Dependencies
- bash 5.2.21-2ubuntu4; coreutils 9.4-3ubuntu6.3
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
2026-02-02
Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.