UNIX Timestamp Conversion

Tool Introduction

The UNIX timestamp conversion tool is an efficient and convenient online tool designed to help users perform bidirectional conversions between Date/Time and UNIX timestamps. It supports converting any specified date and time to second-level or millisecond-level UNIX timestamps, and vice versa. Whether it is for development debugging, data analysis, or daily time query, this tool can provide fast and accurate conversion services.

Origin and Use of UNIX Timestamps

A UNIX timestamp, also known as a POSIX timestamp or Epoch time, is the number of seconds or milliseconds that have elapsed since 00:00:00 UTC (Coordinated Universal Time) on January 1, 1970, excluding leap seconds. It is an integer value widely used in computer systems, databases, network protocols, and other fields to represent and record time points. Due to its simplicity, global uniformity (based on UTC), and ease of calculation, the UNIX timestamp is one of the preferred ways to process and store time information.

• Origin: Originated from the UNIX operating system, which efficiently manages and records time internally through an integer.
• Uses:
• Data Storage: Stores time in databases for easy sorting and cross-timezone processing.
• API Interface: When exchanging time data between different systems, UNIX timestamps are usually used to avoid time zone and format issues.
• Log Recording: Marks the time of events in log files for easy traceability and analysis.
• Time Calculation: Facilitates addition and subtraction operations on time, such as calculating time intervals.

How to Use

1. Date to UNIX Timestamp:
   • Select or manually enter the date and time you need to convert in the “Date” input box (the current local time is displayed by default).
   • Select the timestamp unit you want to generate in the “Type” option: “Second” or “Millisecond”.
   • The “Timestamp” input box will display the converted UNIX timestamp in real time.
2. UNIX Timestamp to Date:
   • Enter the UNIX timestamp you have in the “Timestamp” input box.
   • Select the unit of the timestamp you entered in the “Type” option: “Second” or “Millisecond”.
   • The “Date” input box will display the converted date and time in real time.

Format and requirements for input parameters:

• Date: Uses the datetime-local format, for example: 2023-10-27T10:30. Usually accurate to the second. If more precise millisecond-level conversion is required, it is recommended to directly enter the millisecond-level timestamp for reverse operation.
• Timestamp: Pure number, integer form. Second-level timestamps are usually 10-digit numbers, and millisecond-level timestamps are usually 13-digit numbers.
• Type: Must select “Second” or “Millisecond” to ensure correct conversion accuracy.

Format of output results:

• Date: Output as a local format date and time string, for example: 2023-10-27T10:30:00.
• Timestamp: Output as a pure number (integer), representing the number of seconds or milliseconds since January 1, 1970.

Usage Examples

The following examples are demonstrated based on the local time zone UTC+8:

• Example 1: Date to Second-Level UNIX Timestamp
  • Operation: Enter 2023-10-27T10:30:00 in the “Date” box, and select “Second” for “Type”.
  • Expected Output: The “Timestamp” box displays 1698373800.
  • Explanation: Local time 2023-10-27 10:30:00 (UTC+8) corresponds to UTC time 2023-10-27 02:30:00, and its second-level timestamp is 1698373800.
• Example 2: Date to Millisecond-Level UNIX Timestamp
  • Operation: Enter 2023-10-27T10:30:00 in the “Date” box, and select “Millisecond” for “Type”.
  • Expected Output: The “Timestamp” box displays 1698373800000.
  • Explanation: Multiply the second-level timestamp by 1000 to get the millisecond-level timestamp.
• Example 3: Second-Level UNIX Timestamp to Date
  • Operation: Enter 1698373800 in the “Timestamp” box, and select “Second” for “Type”.
  • Expected Output: The “Date” box displays 2023-10-27T10:30:00.
  • Explanation: Convert the second-level timestamp back to local date and time.
• Example 4: Millisecond-Level UNIX Timestamp to Date
  • Operation: Enter 1698373800000 in the “Timestamp” box, and select “Millisecond” for “Type”.
  • Expected Output: The “Date” box displays 2023-10-27T10:30:00.
  • Explanation: Convert the millisecond-level timestamp back to local date and time. The date input box usually only displays to the second.

Common Questions

• Q: What is a UNIX timestamp? A: A UNIX timestamp is the number of seconds or milliseconds that have elapsed since 00:00:00 (midnight) on January 1, 1970, Greenwich time (UTC/GMT), excluding leap seconds. It is the standard method of representing time in computer systems.
• Q: What timestamp units are supported? A: This tool supports converting date and time to UNIX timestamps (second-level or millisecond-level), and also supports converting UNIX timestamps (second-level or millisecond-level) back to date and time.
• Q: Does timestamp conversion consider time zones? A: The “Date” input box of this tool is local date and time (datetime-local), which means that you are entering the local time of your current operating system. The conversion result will be calculated and displayed based on the local time zone of your browser or operating system. For example, if you enter local time, it will first be converted to UTC time, and then the UNIX timestamp will be calculated. The reverse conversion is also the same.
• Q: When entering a millisecond-level timestamp to convert to a date, why is the date only accurate to the second? A: The datetime-local type input box usually only displays to the second in most browsers. When you enter a millisecond-level timestamp and convert it to a date, although milliseconds may be processed internally, the display will truncate or ignore the millisecond part and only display to the second.

Precautions

• Date Format: Please ensure that the format entered or selected in the “Date” input box is a valid local date and time format (for example, YYYY-MM-DDTHH:MM:SS). Incorrect formats may cause conversion failure or incorrect results.
• Time Zone Settings: The conversion result will be affected by the local time zone settings of your browser or operating system. If you need to handle conversions in a specific time zone, please ensure that your system time zone settings are correct, or perform manual time zone adjustments.
• Timestamp Accuracy: The datetime-local input box is usually only accurate to the second. If you need to perform millisecond-level date to timestamp conversion, this tool will default the millisecond part to 000. If you need accuracy to the millisecond, it is recommended that you directly enter the millisecond-level timestamp for reverse conversion.
• Timestamp Range: UNIX timestamps are usually represented by 32-bit or 64-bit integers, and there are representation range limitations. Date and time outside this range (such as the very distant past or future) may not be converted correctly.