Re-format a date with tokens
Type any parseable date and a pattern of tokens (YYYY, MM, DD, HH, mm, ss, A) to produce a custom output. Runs entirely in your browser.
How to format a date
Pattern tokens are case-sensitive — YYYY for 4-digit year, MM for padded month, mm for padded minutes.
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Paste any date
ISO 8601, RFC 2822, or any string Date.parse() accepts.
Parsing is strict-but-tolerant — comments and trailing commas are accepted on input where the source format historically permits them; output stays canonical.
inputstricttolerantliveparseinput · sourceiso · live2026-01-15T09:30:00Z
loaded · parsedtarget · ready - 02
Pick a pattern
Type your own or click a preset chip in the toolbar.
Conversion preserves type information where the target supports it (numbers stay numeric, booleans stay boolean) so the destination parser never has to re-coerce.
patterntype-preservinglosslesslivememoisedtokens · optionsset · liveYYYY-MM-DD HH:mm
options applied · liveround-trip - 03
Live format
Output updates as you edit either field.
Re-encoding is idempotent: running output back through the same converter produces the same bytes, which keeps round-trips git-friendly.
liveidempotentround-tripdiff-cleandeterministicout · convertedfmt · ready2026-01-15 09:30
converted · livediff-clean - 04
Copy result
Drop into logs, filenames, or report headers.
Copy writes via
navigator.clipboard.writeText; downloads use the target’s native MIME so editors apply the right syntax highlighting on open.copyclipboardtarget MIMEblobclient-side✓ · copiedready · doneCopied
shipped · ready to shipsuccess
Converting between formats, safely
Pick the strictest source format
Lossy formats hide bugs. Choose JSON or YAML as your source-of-truth, convert downstream as needed.
Round-trip in CI
If your converter is idempotent, your CI can verify A → B → A equals the original. Catches subtle data loss.
Numbers vs strings differ
YAML/TOML have a number type; CSV doesn’t. Quote IDs in CSV to keep leading-zero values intact.
Watch character encoding
Source format may be Latin-1 / Windows-1252; target should be UTF-8. Convert encoding before structure.
Preserve comments where you can
YAML and TOML support comments. Don’t silently drop them — they often encode intent.
Schema-aware beats blind
Use a schema to guide conversion. Field types, required-ness, and defaults survive better with structure.
When to re-format dates
Filenames, reports, log filters, exports.
Filenames
Generate sortable YYYY-MM-DD prefixes. Type information survives: numbers stay numeric, booleans stay boolean, strings stay strings. The destination parser doesn't have to re-coerce, which avoids the "'true' becomes "true"" bug class.
round-trip safeReports
Match a regional date style your audience expects. Run output back through the inverse converter to verify idempotent round-trips in CI. A → B → A should produce byte-identical input — if it doesn't, you've found data loss.
type-preservingLog filtering
Build a search string that matches your log lines. Comments and metadata survive where the target format supports them (YAML, TOML, HCL). The tool doesn't silently drop intent-encoded annotations, which keeps your config self-documenting.
schema-awareAPI formatting
Match the exact pattern an external API wants. Pair with a schema (JSON Schema, OpenAPI, Zod, Pydantic) to catch shape drift on either side. Catch breaking changes at conversion time rather than at runtime in production.
losslessCron preview
See what 'today at HH:mm' will look like. Output respects target-format conventions: quoting in CSV, indent in YAML, brackets in JSON. Existing parsers don't need patches, and the result drops into legacy pipelines unchanged.
diff-cleanLocale checks
Compare DD/MM vs MM/DD ordering at a glance. Encoding-aware: handles UTF-8 vs UTF-16 vs Latin-1 / Windows-1252 transparently. The character-set surprise that breaks "works on my machine" doesn't apply here.
spec-gradeFrequently asked questions
Something missing?
Tell us what you need. We ship the top requests every two weeks.