era

README

Era

CLI tool for managing querying and manipulating date times written in Go

Mirrored on GitHub at whiite/era from GitLab at monokuro/era

Install

Installation currently requires you have go installed on your system

To install:

go install gitlab.com/monokuro/era@latest

Usage

Use era help to see available commands and flags otherwise here are some examples:

# Prints the current time
era now

# Prints the current time as a unix timestamp
era now --formatter unix

# Prints the current date and time using Luxon and Moment formatting tokens in Tokyo's time zone
era now --timezone Asia/Tokyo --formatter luxon "h:mm d/L/yyyy"
era now --timezone Asia/Tokyo --formatter moment "h:mm D/M/Y"

# Parse and convert a time from one format to another
era parse --formatter unix 1746799240 --format iso # 2025-05-09T15:00:40+01:00
era parse --formatter iso 2025-05-09T15:00:40+01:00 --format moment "h:mm D/M/Y" # 3:00 9/5/2025

# Prints the available supported tokens and descriptions for the strptime/strftime formatter
era tokens --formatter strftime

# Convert and parse durations
era duration 90s --output minutes # 1.5
# Supports multiple units and separators
era duration 1h5_000ms --output ms --separator=_ # 3_605_000

# Prints help for the specific CLI command
era help <sub command>

Supported Formatters

More is planned to be added in the future as I come across them but these three I've found I've used the most.

Correct escape sequences are supported for all

Note: Not every token is implemented fully yet. Most work as intended; some locale specific formats are hardcoded to the UK or English versions but all are covered by tests

• moment
  • Some locale specific formats may return slightly different strings to the real moment
• luxon
  • Missing support for tokens:
    • ZZZZ - full offset name e.g. "Eastern Standard Time"
    • TTTT - Localised 24 hour time with full time zone name
    • f, ff, fff, ffff - localised date and time
    • F, FF, FFF, FFFF - localised date and time with seconds
• strftime (tokens used in a variety of languages including the date CLI)
  • Full compatibility via C FFI bindings to the strftime function
  • An alternative Go implementation (using go:strftime as the formatter)
    • Missing true locale support with some tokens such as %Ec, %c currently hardcoded to the UK representation
• go (time package format)
  • Full support as this CLI tool is written in Go and uses the standard library time package

Compatibility table

Feature	Go	strftime/strptime	Go strftime/strptime	Luxon	Moment
Formatting with tokens	All ✅	All ✅	All ✅	Most	All ✅
Token descriptions	All ✅	All ✅	All ✅	All ✅	All ✅
Locale support	N/A	Yes ✅	Some	Some	Some
Parsing tokens	All ✅	All ✅	Some	No ❌	No ❌

Under consideration

• Better UX for locale names - (possibly using: https://pkg.go.dev/github.com/zlasd/tzloc)
• A "describe"/"explain" command for describing the tokens provided according to the specified formatter