What is a Unix Timestamp Converter?
A Unix timestamp converter is an essential tool for developers, system administrators, and anyone working with time-based data in computer systems. Our free online Unix timestamp converter allows you to seamlessly convert between Unix timestamps (Epoch time) and human-readable dates in multiple formats and timezones. Whether you're debugging applications, analyzing logs, or working with APIs, our tool makes timestamp conversion instant and accurate.
Understanding Unix Timestamps
Unix timestamps represent time as the number of seconds (or milliseconds) that have passed since January 1, 1970, 00:00:00 UTC, known as the Unix Epoch. This simple numeric representation makes it easy to:
- Store dates and times efficiently in databases
- Calculate time differences with simple subtraction
- Compare dates without timezone complications
- Transmit time data across different systems and languages
- Sort chronological data quickly
Seconds vs Milliseconds Timestamps
Seconds Timestamp (10 digits)
Traditional Unix timestamps use seconds precision with 10 digits. Example: 1234567890 represents February 14, 2009, 12:31:30 AM UTC. This format is commonly used in:
- Linux/Unix system calls and shell commands
- PHP date functions (time(), strtotime())
- Python's time.time()
- Many REST APIs and backend services
- Database timestamp columns
Milliseconds Timestamp (13 digits)
Modern applications often use milliseconds precision with 13 digits. Example: 1234567890000 represents the same date with millisecond precision. This format is standard in:
- JavaScript's Date.now() and getTime()
- Java's System.currentTimeMillis()
- MongoDB's timestamp fields
- Node.js and web applications
- Microservices requiring high precision
Common Use Cases
1. Log Analysis and Debugging
Server logs, application logs, and system logs often record events with Unix timestamps. Convert these timestamps to readable dates to understand when events occurred, identify patterns, troubleshoot issues, and correlate events across different systems. Our tool's relative time feature helps you quickly see "3 hours ago" or "2 days ago" for context.
2. Database Development
Most databases store timestamps as Unix time for efficiency. When querying or inserting data, you need to convert between human-readable dates and timestamps. Use our converter to generate correct timestamp values for SQL queries, validate stored timestamps, or understand query results.
3. API Development and Testing
REST APIs frequently use Unix timestamps in request/response payloads, authentication tokens (JWT exp claims), rate limiting windows, and cache expiration times. Convert timestamps to verify API responses, test edge cases, or debug authentication issues.
4. Scheduled Tasks and Cron Jobs
Calculate exact execution times for scheduled tasks, determine next run times, measure task duration, or plan maintenance windows. Convert between readable schedules and timestamps for accurate task scheduling.
5. Date Range Filtering
Generate timestamp ranges for data queries, analytics dashboards, report generation, or search filters. Our tool helps you quickly find timestamps for "start of day," "end of month," or any specific date range.
6. Timezone Conversion
Unix timestamps are timezone-agnostic (always UTC), but displaying them requires timezone awareness. Our tool supports 11 major timezones including UTC, EST, PST, GMT, CET, JST, and more, helping you see how the same timestamp appears to users in different locations.
Timestamp Formats Supported
ISO 8601
International standard format: 2024-01-15T14:30:00.000Z. This format is recommended for data interchange, API responses, and configuration files. It's unambiguous, sortable, and widely supported across programming languages and databases.
RFC 2822
Email and HTTP header format: Mon, 15 Jan 2024 14:30:00 GMT. Used in HTTP headers (Last-Modified, Expires), email headers (Date), and RSS feeds. Human-readable but longer than ISO 8601.
Relative Time
Human-friendly format: "3 hours ago", "in 2 days", "just now". Perfect for user interfaces, social media feeds, notification systems, and activity logs. Our tool automatically calculates and updates relative time from the current moment.
Component Breakdown
Individual year, month, day, hour, minute, second, and weekday components. Useful for:
- Building custom date displays
- Extracting specific parts for calculations
- Validating date components
- Creating calendar interfaces
Working with Different Programming Languages
JavaScript / Node.js
Get current timestamp:
// Milliseconds const now = Date.now(); // 1704467400000 // Seconds const nowSeconds = Math.floor(Date.now() / 1000); // 1704467400 // Convert timestamp to date const date = new Date(1704467400000); console.log(date.toISOString()); // 2024-01-15T14:30:00.000Z // Convert date to timestamp const timestamp = new Date('2024-01-15').getTime();Python
Working with timestamps in Python:
import time import datetime # Get current timestamp (seconds) now = time.time() # 1704467400.123 # Convert timestamp to datetime dt = datetime.datetime.fromtimestamp(1704467400) print(dt) # 2024-01-15 14:30:00 # Convert datetime to timestamp timestamp = datetime.datetime(2024, 1, 15).timestamp()PHP
PHP timestamp functions:
// Get current timestamp (seconds) $now = time(); // 1704467400 // Convert timestamp to date $date = date('Y-m-d H:i:s', 1704467400); echo $date; // 2024-01-15 14:30:00 // Convert date to timestamp $timestamp = strtotime('2024-01-15 14:30:00');Java
Java timestamp operations:
// Get current timestamp (milliseconds) long now = System.currentTimeMillis(); // 1704467400000 // Convert timestamp to date Date date = new Date(1704467400000L); System.out.println(date); // Convert date to timestamp Instant instant = Instant.parse("2024-01-15T14:30:00Z"); long timestamp = instant.toEpochMilli();Important Timestamp Concepts
Unix Epoch (January 1, 1970)
The starting point for Unix timestamps. Timestamp 0 represents 1970-01-01 00:00:00 UTC. Negative timestamps represent dates before 1970. The choice of this date was arbitrary, based on when Unix was being developed.
UTC vs Local Time
Unix timestamps are always measured in UTC (Coordinated Universal Time), regardless of your local timezone. When displaying timestamps to users, convert from UTC to the appropriate local timezone. Always store timestamps in UTC and convert for display.
Leap Seconds
Unix timestamps don't account for leap seconds (occasional 1-second adjustments to UTC). This means there can be very slight discrepancies between Unix time and actual elapsed time for precision-critical applications spanning decades.
Year 2038 Problem (Y2K38)
32-bit systems can only store timestamps up to 2,147,483,647 seconds (January 19, 2038, 03:14:07 UTC). After this, the value overflows to negative, representing dates in 1901. Modern 64-bit systems solve this, supporting dates billions of years into the future.
Best Practices for Working with Timestamps
1. Always Store in UTC
Store all timestamps in UTC in your database. Never store local time or timezone-adjusted times. Convert to local time only when displaying to users. This prevents ambiguity during daylight saving time transitions and simplifies timezone conversions.
2. Use Appropriate Precision
Choose seconds for most applications (file systems, logs, user events). Use milliseconds for high-frequency events (financial transactions, real-time gaming). Use microseconds or nanoseconds only when absolutely necessary (scientific measurements, high-frequency trading).
3. Validate Timestamp Ranges
Check that timestamps are within reasonable ranges. Reject impossible future dates (e.g., year 9999) and unreasonably old dates (before your application existed). This catches bugs from incorrect unit conversion (seconds vs milliseconds).
4. Handle Timezone Conversions Carefully
Use established libraries (moment.js, date-fns, luxon, pytz) for timezone conversions. Don't try to implement timezone logic yourself—it's complex with DST rules, historical changes, and regional variations.
5. Document Timestamp Units
Clearly document whether your API uses seconds or milliseconds. Use descriptive field names like created_at_ms or updated_at_seconds. Consider including the unit in API documentation and error messages.
Common Timestamp Calculations
Adding/Subtracting Time
- Add 1 day: timestamp + 86400 (seconds) or +86400000 (milliseconds)
- Add 1 hour: timestamp + 3600 (seconds) or +3600000 (milliseconds)
- Add 1 week: timestamp + 604800 (seconds) or +604800000 (milliseconds)
- Subtract 30 days: timestamp - 2592000 (seconds)
Time Differences
Calculate elapsed time by subtracting timestamps: end_timestamp - start_timestamp. The result is in the same unit (seconds or milliseconds) as the input timestamps. Convert to hours by dividing by 3600, or to days by dividing by 86400.
Start/End of Day
To get midnight (start of day): truncate the timestamp to remove time components. In most languages, create a date object, set hours/minutes/seconds to 0, then convert back to timestamp. For end of day, set to 23:59:59 or add 86399 seconds to start of day.
Why Choose Our Unix Timestamp Converter?
- Live Updates: See the current Unix timestamp updating in real-time every second
- Bidirectional Conversion: Convert timestamp to date or date to timestamp with equal ease
- Multiple Formats: Get results in ISO 8601, RFC 2822, relative time, and component breakdown
- Timezone Support: Choose from 11 major timezones including UTC, EST, PST, GMT, CET, JST
- Seconds & Milliseconds: Switch between units instantly
- One-Click Copy: Copy any format to clipboard with visual feedback
- Quick Presets: Instantly jump to Unix Epoch, tomorrow, yesterday
- No Installation: Works entirely in your browser, no downloads needed
- Mobile Friendly: Perfect for on-the-go timestamp conversions
- Completely Free: No registration, no limits, no ads