Logs say 1704672000. Brain says “when was that?!” Here’s how to translate epoch time to actual human time.

Convert Unix timestamp to local time

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# Using date command
date -d @1704672000
# Output: Sun Jan  7 20:10:00 IST 2024

# Custom format
date -d @1704672000 '+%Y-%m-%d %H:%M:%S'
# Output: 2024-01-07 20:10:00

# With timezone
TZ='America/New_York' date -d @1704672000

Convert local time to Unix timestamp

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# Current time
date +%s
# Output: 1704672000

# Specific date to timestamp
date -d "2024-01-07 20:10:00" +%s
# Output: 1704672000

# Different date formats
date -d "Jan 7 2024" +%s
date -d "2024-01-07T20:10:00" +%s

Bulk conversion (from file or variable)

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# Convert multiple timestamps
echo "1704672000" | while read ts; do
  date -d @$ts '+%Y-%m-%d %H:%M:%S'
done

# From file with timestamps
cat timestamps.txt | while read ts; do
  echo "Timestamp: $ts -> $(date -d @$ts)"
done

macOS/BSD date syntax

macOS uses different syntax:

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# Unix timestamp to local time
date -r 1704672000

# Local time to Unix timestamp
date -j -f "%Y-%m-%d %H:%M:%S" "2024-01-07 20:10:00" +%s

Millisecond timestamps

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# Convert millisecond timestamp (divide by 1000)
ts_ms=1704672000000
date -d @$((ts_ms / 1000))

# Get current time in milliseconds
date +%s%3N

Quick one-liner for logs

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# Replace timestamps in log file
awk '{cmd="date -d @"$1; cmd | getline d; close(cmd); $1=d; print}' logfile.txt