feat(DateTime): add helper to interpret input without timezone as utc time otherwise convert to utc

src/constants/timeZone.ts

@@ -1,3 +1 @@
-import type {TimeZone} from '../typings';
-
-export const UtcTimeZone: TimeZone = 'UTC';
+export const UtcTimeZone = 'UTC';

src/dateTime/dateTime.ts

@@ -264,22 +264,13 @@ class DateTimeImpl implements DateTime {
         asFloat?: boolean | undefined,
     ): number {
         const value = DateTimeImpl.isDateTime(amount) ? amount.valueOf() : amount;
-        // value:
-        //   DateTimeInput !== dayjs.ConfigType;
-        //   Array<string, number> !== [number?, number?, number?, number?, number?, number?, number?]
-        // unit:
-        //   the same problem as for startOf
-        // @ts-expect-error
         return this._date.diff(value, unit, asFloat);
     }
     fromNow(withoutSuffix?: boolean | undefined): string {
         return this._date.fromNow(withoutSuffix);
     }
     from(formaInput: DateTimeInput, withoutSuffix?: boolean): string {
         const value = DateTimeImpl.isDateTime(formaInput) ? formaInput.valueOf() : formaInput;
-        // DateTimeInput !== dayjs.ConfigType;
-        // Array<string, number> !== [number?, number?, number?, number?, number?, number?, number?]
-        // @ts-expect-error
         return this._date.from(value, withoutSuffix);
     }
     locale(): string;
@@ -569,14 +560,8 @@ function getTimestamp(input: DateTimeInput, format?: string, lang?: string) {
         ts = Number(input);
     } else {
         const localDate = format
-            ? // DateTimeInput !== dayjs.ConfigType;
-              // Array<string, number> !== [number?, number?, number?, number?, number?, number?, number?]
-              // @ts-expect-error
-              dayjs(input, format, locale, STRICT)
-            : // DateTimeInput !== dayjs.ConfigType;
-              // Array<string, number> !== [number?, number?, number?, number?, number?, number?, number?]
-              // @ts-expect-error
-              dayjs(input, undefined, locale);
+            ? dayjs(input, format, locale, STRICT)
+            : dayjs(input, undefined, locale);
 
         ts = localDate.valueOf();
     }
@@ -623,3 +608,25 @@ export function dateTime(opt?: {
 
     return date;
 }
+
+export function dateTimeUtc(opt?: {input?: DateTimeInput; format?: FormatInput; lang?: string}) {
+    const {input, format, lang} = opt || {};
+
+    const locale = dayjs.locale(lang || settings.getLocale(), undefined, true);
+
+    let ts: number;
+    if (DateTimeImpl.isDateTime(input) || typeof input === 'number' || input instanceof Date) {
+        ts = Number(input);
+    } else {
+        ts = dayjs.utc(input, format, STRICT).valueOf();
+    }
+
+    const date = createDateTime({
+        ts,
+        timeZone: UtcTimeZone,
+        offset: 0,
+        locale,
+    });
+
+    return date;
+}

src/dateTime/dateTimeUtc.test.ts

@@ -0,0 +1,63 @@
+import MockDate from 'mockdate';
+
+import {settings} from '../settings';
+
+import {dateTimeUtc, isDateTime} from './dateTime';
+
+const MOCKED_DATE = '2021-08-07T12:10:00';
+
+beforeEach(() => {
+    MockDate.set(MOCKED_DATE);
+});
+
+afterEach(() => {
+    MockDate.reset();
+    settings.updateLocale({weekStart: 1, yearStart: 1});
+});
+
+describe('DateTimeUtc', () => {
+    describe('isDateTime', () => {
+        it('should return true in case of DateTime checking', () => {
+            const date = dateTimeUtc();
+            const result = isDateTime(date);
+            expect(result).toEqual(true);
+        });
+    });
+
+    describe('dateTimeUtc', () => {
+        it('should return now date in case of absence of input arg', () => {
+            const date = dateTimeUtc();
+            const now = new Date();
+            expect(date.toISOString()).toEqual(now.toISOString());
+        });
+
+        it('should return DateTime with UTC timeZone', () => {
+            const zone = dateTimeUtc().timeZone();
+            expect(zone).toEqual('UTC');
+        });
+
+        it('should return 0 offset', () => {
+            const date = dateTimeUtc();
+            const offset = date.utcOffset();
+            expect(offset).toEqual(0);
+        });
+
+        test.each<[string, string]>([
+            ['2023-12-31', '2023-12-31T00:00:00.000Z'],
+            ['2023-12-31T01:00', '2023-12-31T01:00:00.000Z'],
+            ['2023-12-31T01:00Z', '2023-12-31T01:00:00.000Z'],
+            ['2023-12-31T03:00+02:00', '2023-12-31T01:00:00.000Z'],
+        ])('input option (%p)', (input, expected) => {
+            const date = dateTimeUtc({input}).toISOString();
+            expect(date).toEqual(expected);
+        });
+
+        test.each<[string, string, string]>([
+            ['31.12.2023', 'DD.MM.YYYY', '2023-12-31T00:00:00.000Z'],
+            ['31.12.2023 01:00', 'DD.MM.YYYY HH:mm', '2023-12-31T01:00:00.000Z'],
+        ])('input (%p) format (%p)', (input, format, expected) => {
+            const date = dateTimeUtc({input, format}).toISOString();
+            expect(date).toEqual(expected);
+        });
+    });
+});

src/datemath/datemath.test.ts

@@ -17,7 +17,7 @@ describe('DateMath', () => {
     const format = 'YYYY-MM-DDTHH:mm:ss.SSSZ';
     let clock: SinonFakeTimers;
 
-    describe('Ошибки', () => {
+    describe('Issues', () => {
         it('should return undefined if passed empty string', () => {
             expect(dateMath.parse('')).toBe(undefined);
         });
@@ -134,7 +134,7 @@ describe('DateMath', () => {
         });
     });
 
-    describe('Парс части относительной даты, начинающейся после now', () => {
+    describe('Parsing part after now', () => {
         it('should handle negative time', () => {
             const date = dateMath.parseDateMath('-2d', dateTime({input: [2014, 1, 5]}));
             expect(date?.valueOf()).toEqual(dateTime({input: [2014, 1, 3]}).valueOf());

src/datemath/datemath.ts

@@ -57,7 +57,7 @@ export function parse(
                 mathString = text.substring(index + 2);
             }
 
-            time = dateTime({input: parseString});
+            time = dateTime({input: parseString, timeZone});
         }
 
         if (!mathString.length) {
@@ -71,7 +71,7 @@ export function parse(
         }
 
         if (isDate(text)) {
-            return dateTime({input: text});
+            return dateTime({input: text, timeZone});
         }
 
         return undefined;

src/dayjs/dayjs.d.ts

@@ -0,0 +1,10 @@
+import 'dayjs';
+
+declare module 'dayjs' {
+    interface ConfigTypeMap {
+        // to fix inconsistent typing between dayjs and DateTime
+        // dayjs expects [number?, number?, number?, number?, number?, number?, number?]
+        // but DateTime allows Array<string | number>
+        dateTimeArray: Array<string | number>;
+    }
+}

src/index.ts

@@ -1,6 +1,7 @@
-export {dateTime, isDateTime} from './dateTime';
+export {dateTime, dateTimeUtc, isDateTime} from './dateTime';
 export {isValid} from './datemath';
 export {dateTimeParse} from './parser';
-export {getTimeZonesList, guessUserTimeZone} from './timeZone';
+export {getTimeZonesList, guessUserTimeZone, isValidTimeZone, timeZoneOffset} from './timeZone';
 export type {DateTime, DateTimeInput} from './typings';
 export {settings} from './settings';
+export {UtcTimeZone} from './constants';