sdate

sdate is a command-line tool that generates a timestamp using a Splunk-like relative time and snap operation.

Features

• Generates a timestamp from the current time or a specified base time.
• Supports Splunk-like relative time and snap operations, such as -1d@d.
• Supports output in Go language's time layout string format or UNIXTIME (Epoch Time).
• Provides a detailed help message via the --help option.
• Allows specifying the output timezone.
• Shows version information via the --version option.

Supported Time Units

• s: seconds
• m: minutes
• h: hours
• d: days
• w: weeks (Monday is assumed to be the start of the week)
• M: months
• y: years

Installation

With Go and Make installed, build the tool by running the following command.

make build

This will create the sdate executable in the current directory.

For cross-compilation or creating a macOS universal binary, use the following commands:

# Build for Linux, Windows, and macOS (Intel)
make release

# Create a macOS universal binary (Apple Silicon + Intel)
make universal-mac

Usage

The basic usage is as follows:

./sdate [operation] [--base <time>] [--format <layout>] [--output-tz <timezone>]

Arguments and Options

• [operation] (optional): A string specifying the operation to perform. It can be a relative time, a snap, or a combination.

  • Examples: -1d@d (beginning of the day, one day ago), @h (beginning of the current hour), +2h (2 hours from now)

• --base (optional): The base time for the calculation. If not specified, the current time is used.

  • Supported formats:
    • RFC3339: 2023-10-27T10:00:00Z
    • Simple Date: 2023-10-27
    • UNIXTIME: 1698372000
    • TZ-aware: TZ=America/New_York 2023-10-27T10:00:00

• --format (optional): The output format for the final timestamp. The default is RFC3339.

  • You can use Go's time layout string (e.g., '2006-01-02 15:04:05').
  • You can also specify a more intuitive format like 'YYYY/MM/DD hh:mm:ss'.
  • You can also specify 'unix' or 'epoch' to output as a Unix timestamp.

• --output-tz (optional): Specifies the timezone for the output timestamp.

  • Example: 'Asia/Tokyo', 'America/New_York'.

• --version: Show version information.

• --help: Show detailed help message.

Supported Format Metacharacters

• YYYY: 4-digit year
• YY: 2-digit year
• MM: 2-digit month
• M: 1-digit month
• DD: 2-digit day
• D: 1-digit day
• hh: 24-hour
• mm: minute
• ss: second
• SSS: millisecond
• UUU: microsecond
• a: AM/PM
• TZ: Timezone abbreviation (e.g., JST)
• ZZ: Timezone offset with colon (e.g., +09:00)
• ZZZ: Timezone offset without colon (e.g., +0900)

Examples

# Show version
./sdate --version

# Output current time in a more intuitive format
./sdate --format 'YYYY/MM/DD hh:mm:ss'

# Output current time with milliseconds
./sdate --format 'YYYY-MM-DD hh:mm:ss.SSS'

# Calculate 2 hours after a specified time in a specific timezone, then output in another timezone
./sdate +2h --base 'TZ=America/New_York 2023-10-27T10:00:00' --output-tz Asia/Tokyo --format 'YYYY-MM-DD hh:mm:ss ZZ'

# Output the current time with timezone abbreviation
./sdate --format 'YYYY-MM-DD hh:mm:ss TZ'

# Output the current time with timezone offset (with colon)
./sdate --format 'YYYY-MM-DD hh:mm:ss ZZ'

# Output the current time with timezone offset (without colon)
./sdate --format 'YYYY-MM-DD hh:mm:ss ZZZ'

Development

Testing

To run the tests, use the following command:

make test