@formatjs/intl-utils
v3.8.4Intl Utils
Provide i18n utilities.
API
selectUnit
This function determines the best fit
unit based on a specific set of customizable thresholds.
function selectUnit(
from: Date | number,
to: Date | number = Date.now(),
thresholds = DEFAULT_THRESHOLDS
): {value: number; unit: Unit};
where thresholds
has the shape of:
interface Threshold {
second: number;
minute: number;
hour: number;
day: number;
}
month
& year
are based on calendar, thus not customizable.
Example:
import {selectUnit} from '@formatjs/intl-utils';
selectUnit(Date.now() - 1000); // { value: -1, unit: 'second' }
selectUnit(Date.now() - 44000); // { value: -44, unit: 'second' }
selectUnit(Date.now() - 50000); // { value: 1, unit: 'minute' }
Caveats
selectUnit
is meant to be a stepping stone from the old IntlRelativeFormat
to the officially spec-ed Intl.RelativeTimeFormat
. Therefore we don't recommend using this for an extended period of time because of ambiguous editorial issues such as:
From 2019/01/01 -> 2018/11/01 can technically be
last year
,2 months ago
ora quarter ago
.From 2019/01/02 6am to 2019/01/01 11pm can also be
7 hours ago
oryesterday
. Timezone further complicates the issue.
The examples above have not even tackled the differences in non-Gregorian calendars. There is an issue opened upstream in the spec that potentially introduces a best fit
algorithm. Therefore, we recommend that you implement your own version of selectUnit
that matches your editorial expectation. This will be removed in future releases.