parse_datetime

A Rust crate for parsing human-readable relative time strings and converting them to a Duration, or parsing 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 this to your Cargo.toml:

[dependencies]
parse_datetime = "0.4.0"

Then, import the crate and use the from_str and from_str_at_date functions:

use parse_datetime::{from_str, from_str_at_date};
use chrono::Duration;

let duration = from_str("+3 days");
assert_eq!(duration.unwrap(), Duration::days(3));

let today = Utc::today().naive_utc();
let yesterday = today - Duration::days(1);
assert_eq!(
    from_str_at_date(yesterday, "2 days").unwrap(),
    Duration::days(1)
);

For DateTime parsing, import the parse_datetime module:

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

let dt = from_str("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 from_str and from_str_at_date functions support the following formats for relative time:

• 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")

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

Duration

The from_str and from_str_at_date functions return:

• Ok(Duration) - If the input string can be parsed as a relative time
• Err(ParseDurationError) - If the input string cannot be parsed as a relative time

This function will return Err(ParseDurationError::InvalidInput) if the input string cannot be parsed as a relative time.

parse_datetime

The from_str function returns:

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

Fuzzer

To run the fuzzer:

$ cargo fuzz run fuzz_from_str

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.