taitimestamp

A JavaScript/TypeScript library for manipulating TAI timestamps to nanosecond precision (e.g., for representing PTP time).

Licensed under the Apache License and given back to the community by 1500 Cloud.

Installation

npm i --save @1500cloud/taitimestamp

or

yarn add @1500cloud/taitimestamp

Usage

e.g.,

import { now } from "@1500cloud/taitimestamp";

or

const { now } = require("@1500cloud/taitimestamp");

The type TaiTimestamp is used to represent this in TypeScript. This is officially an object, but please use the built-in helpers to convert other domains.

now(): TaiTimestamp

Returns a string representing a TAI Timestamp for the current date. This is limited to the millisecond resolution of the underlying JavaScript platform.

taiTimestampFromJsTime(number): TaiTimestamp

Takes a JavaScript timestamp (e.g., new Date().getTime()) and converts it to a TAI Timestamp object (limited to the millisecond precision of a JavaScript date object).

taiTimestampFromString(string): TaiTimestamp | null

This takes a string like "123455.66" which represents a fractional number of seconds since the Unix epoch and converts it into an object. (Strings are used to maintain precision).

taiTimestampFromMediaTimestamp(string): TaiTimestamp | null

This takes a string like "123455:678000000" as used to represent time in the broadcasting domain (e.g., NMOS APIs) and returns a TaiTimestamp object.

taiTimestampFromNanoseconds(BigInt): TaiTimestamp | null

This takes a BigInt number representing the number of nanoseconds and returns a TaiTimestamp object.

taiTimestampToString(TaiTimestamp): string

This converts a TaiTimestamp object to a string representation.

taiTimestampToMediaTimestamp(TaiTimestamp): string

This converts a TaiTimestamp object to a string representation for TAI time as used in broadcasting (e.g., NMOS APIs).

taiTimestampToNanoseconds(TaiTimestamp): BigInt

This returns a BigInt number representing the number of nanoseconds in the TaiTimestamp.

equals(TaiTimestamp, TaiTimestamp): boolean

This compares two timestamp objects and returns if they are equal or not.

gt(TaiTimestamp, TaiTimestamp): boolean

This compares two timestamp objects and returns whether or not the first is greater (later) than the second.

gte(TaiTimestamp, TaiTimestamp): boolean

This compares two timestamp objects and returns whether or not the first is greater (later) than or equal to the second.

lt(TaiTimestamp, TaiTimestamp): boolean

This compares two timestamp objects and returns whether or not the first is less (earlier) than the second.

lte(TaiTimestamp, TaiTimestamp): boolean

This compares two timestamp objects and returns whether or not the first is less (earlier) than or equal to the second.

add(TaiTimestamp, TaiTimestamp): TaiTimestamp

This adds two TaiTimestamps together and returns the result. This only really makes sense if you think of at least one of the TaiTimestamps as a duration, as adding together two absolute times doesn't really make sense.

subtract(TaiTimestamp, TaiTimestamp): TaiTimestamp

This subtracts the second TaiTimestamp from the first and returns the result. This only really makes sense if you think of at least one of the TaiTimestamps as a duration, as subtracting two absolute times doesn't really make sense.

Changelog

Semantic versioning is in use here. Please see the GitHub releases page for change information.

Contributing

Contributions are welcomed in the form of bug reports, bug fixes or feature improvements! If you're unsure on the change you want to make, please open an issue on GitHub first to discuss with the maintainers. Please note that by contributing back to this project you agree to assign copyright of any code modifications to 1500 Services Ltd. Please also see our code of conduct.

• Run unit tests: yarn test
• Run a test watcher: yarn dev