Batch Timestamp Converter

Typical uses

• Log analysis — paste the created_at column of a log export and eyeball the real times.
• API debugging — decode the millisecond timestamps in a JSON response without writing a script.
• Database audits — sanity-check epoch columns before and after a migration.
• Spreadsheet prep — export the decoded times as CSV and join them back to your data.

Bulk conversion in code

Prefer a script? The same logic in two lines:

# shell (GNU date) — decode a file of second-precision timestamps, one per line
while read ts; do date -u -d "@$ts" '+%Y-%m-%d %H:%M:%S UTC'; done < timestamps.txt
# macOS/BSD: date -u -r "$ts" '+%Y-%m-%d %H:%M:%S UTC'

# python
from datetime import datetime, timezone
[datetime.fromtimestamp(int(line), timezone.utc) for line in open('timestamps.txt')]

Watch the unit: if date or fromtimestamp shows dates in 1970, your values are milliseconds — divide by 1,000. The auto-detect above handles this per row.