parse_datetime

A Rust crate for parsing human-readable relative time strings and human-readable datetime strings and converting them to a DateTime.

Features

• Parses a variety of human-readable and standard time formats.
• Supports positive and negative durations.
• Allows for chaining time units (e.g., "1 hour 2 minutes" or "2 days and 2 hours").
• Calculate durations relative to a specified date.
• Relies on Chrono

Usage

Add parse_datetime to your Cargo.toml with:

cargo add parse_datetime

Then, import the crate and use the parse_datetime_at_date function:

use chrono::{Duration, Local};
use parse_datetime::parse_datetime_at_date;

let now = Local::now();
let after = parse_datetime_at_date(now, "+3 days");

assert_eq!(
  (now + Duration::days(3)).naive_utc(),
  after.unwrap().naive_utc()
);

For DateTime parsing, import the parse_datetime function:

use parse_datetime::parse_datetime;
use chrono::{Local, TimeZone};

let dt = parse_datetime("2021-02-14 06:37:47");
assert_eq!(dt.unwrap(), Local.with_ymd_and_hms(2021, 2, 14, 6, 37, 47).unwrap());

Supported Formats

The parse_datetime and parse_datetime_at_date functions support absolute datetime and the following relative times:

• num unit (e.g., "-1 hour", "+3 days")
• unit (e.g., "hour", "day")
• "now" or "today"
• "yesterday"
• "tomorrow"
• use "ago" for the past
• use "next" or "last" with unit (e.g., "next week", "last year")
• combined units with "and" or "," (e.g., "2 years and 1 month", "1 day, 2 hours" or "2 weeks 1 second")
• unix timestamps (for example "@0" "@1344000")

num can be a positive or negative integer. unit can be one of the following: "fortnight", "week", "day", "hour", "minute", "min", "second", "sec" and their plural forms.

Return Values

parse_datetime and parse_datetime_at_date

The parse_datetime and parse_datetime_at_date function return:

• Ok(DateTime<FixedOffset>) - If the input string can be parsed as a datetime
• Err(ParseDateTimeError::InvalidInput) - If the input string cannot be parsed

Fuzzer

To run the fuzzer:

$ cd fuzz
$ cargo install cargo-fuzz
$ cargo +nightly fuzz run fuzz_parse_datetime

License

This project is licensed under the MIT License.

Note

At some point, this crate was called humantime_to_duration. It has been renamed to cover more cases.