techniq · techniq · Jun 10, 2025 · Jun 10, 2025 · Jun 10, 2025
diff --git a/.changeset/funny-days-crash.md b/.changeset/funny-days-crash.md
@@ -0,0 +1,5 @@
+---
+'svelte-ux': patch
+---
+
+refactor: Replace `date-fns` usage with new `@layerstack/utils` date utils (based on d3-time) to reduce bundle size
diff --git a/packages/svelte-ux/package.json b/packages/svelte-ux/package.json
@@ -53,16 +53,15 @@
   "dependencies": {
     "@floating-ui/dom": "^1.7.0",
     "@fortawesome/fontawesome-common-types": "^6.7.2",
-    "@layerstack/svelte-actions": "1.0.1-next.6",
-    "@layerstack/svelte-stores": "1.0.2-next.6",
-    "@layerstack/svelte-table": "1.0.1-next.6",
-    "@layerstack/tailwind": "2.0.0-next.8",
-    "@layerstack/utils": "2.0.0-next.6",
+    "@layerstack/svelte-actions": "1.0.1-next.11",
+    "@layerstack/svelte-stores": "1.0.2-next.11",
+    "@layerstack/svelte-table": "1.0.1-next.11",
+    "@layerstack/tailwind": "2.0.0-next.13",
+    "@layerstack/utils": "2.0.0-next.11",
     "@mdi/js": "^7.4.47",
     "culori": "^4.0.1",
     "d3-array": "^3.2.4",
     "d3-scale": "^4.0.2",
-    "date-fns": "^4.1.0",
     "esm-env": "^1.2.2",
     "immer": "^10.1.1",
     "lodash-es": "^4.17.21",

diff --git a/packages/svelte-ux/src/lib/components/DateButton.svelte b/packages/svelte-ux/src/lib/components/DateButton.svelte
@@ -1,6 +1,5 @@
 <script lang="ts">
   import { createEventDispatcher } from 'svelte';
-  import { isWithinInterval } from 'date-fns';
 
   import { cls } from '@layerstack/tailwind';
   import {
@@ -9,6 +8,7 @@
     type CustomIntlDateTimeFormatOptions,
     type SelectedDate,
     getDateFuncsByPeriodType,
+    isDateWithin,
   } from '@layerstack/utils';
 
   import Button from './Button.svelte';
@@ -50,7 +50,7 @@
         ? selected.some((d) => isSame(date, d))
         : selected instanceof Object
           ? selected.from
-            ? isWithinInterval(date, {
+            ? isDateWithin(date, {
                 start: start(selected.from),
                 end: end(selected.to ?? selected.from),
               })

diff --git a/packages/svelte-ux/src/lib/components/DateField.svelte b/packages/svelte-ux/src/lib/components/DateField.svelte
@@ -1,7 +1,6 @@
 <script lang="ts">
   import { createEventDispatcher, type ComponentProps } from 'svelte';
-  import { parse as parseDate, format as formatDate } from 'date-fns';
-  import { type DisabledDate } from '@layerstack/utils';
+  import { formatDate, parseDate, type DisabledDate } from '@layerstack/utils';
   import { cls } from '@layerstack/tailwind';
 
   import { getComponentSettings, getSettings } from './settings.js';
@@ -54,7 +53,7 @@
   function onInputChange(e: any) {
     inputValue = e.detail.value;
     const lastValue = value;
-    const parsedValue = parseDate(inputValue ?? '', actualFormat, new Date());
+    const parsedValue = parseDate(inputValue ?? '', actualFormat);
     value = isNaN(parsedValue.valueOf()) ? null : parsedValue;
     if (value != lastValue) {
       dispatch('change', { value });

diff --git a/packages/svelte-ux/src/lib/components/DateRange.svelte b/packages/svelte-ux/src/lib/components/DateRange.svelte
@@ -1,5 +1,4 @@
 <script lang="ts">
-  import { isAfter, isBefore, isSameDay } from 'date-fns';
   import { cls } from '@layerstack/tailwind';
   import { omit } from '@layerstack/utils/object';
   import { mdScreen } from '@layerstack/svelte-stores';
@@ -8,6 +7,9 @@
     DayOfWeek,
     getDateFuncsByPeriodType,
     type DisabledDate,
+    isDateAfter,
+    isDateBefore,
+    isSameInterval,
   } from '@layerstack/utils';
   import { getDateRangePresets, type DateRange } from '@layerstack/utils/dateRange';
   import { hasDayOfWeek, replaceDayOfWeek, missingDayOfWeek } from '@layerstack/utils/date';
@@ -72,7 +74,7 @@
   }
 
   function onDateChange(date: Date) {
-    // Apply date-fns function based on type and from/to.
+    // Apply date function based on type and from/to.
     let newSelected = { ...selected, periodType: selectedPeriodType };
 
     const { start, end } = getDateFuncsByPeriodType($localeSettings, selectedPeriodType);
@@ -81,12 +83,12 @@
 
     if (activeDate === 'from') {
       newSelected.from = start(date);
-      if (selected!.to != null && isAfter(date, selected!.to)) {
+      if (selected!.to != null && isDateAfter(date, selected!.to)) {
         newSelected.to = end(date);
       }
     } else {
       newSelected.to = end(date);
-      if (selected!.from != null && isBefore(date, selected!.from)) {
+      if (selected!.from != null && isDateBefore(date, selected!.from)) {
         newSelected.from = start(date);
         newActiveDate = 'to';
       }
@@ -134,9 +136,9 @@
         ].find(
           (x) =>
             x.value.from &&
-            isSameDay(x.value.from, selected!.from!) &&
+            isSameInterval('day', x.value.from, selected!.from!) &&
             x.value.to &&
-            isSameDay(x.value.to, selected!.to!)
+            isSameInterval('day', x.value.to, selected!.to!)
         );
 
         if (prevPeriodTypePreset && newPeriodType) {

diff --git a/packages/svelte-ux/src/lib/components/DateSelect.svelte b/packages/svelte-ux/src/lib/components/DateSelect.svelte
@@ -3,8 +3,12 @@
     TODO:
       - [ ] Set max-height / overflow on MonthListByYear, YearList
   */
-  import { startOfMonth as startOfMonthFunc } from 'date-fns';
-  import { PeriodType, type DisabledDate, type SelectedDate } from '@layerstack/utils';
+  import {
+    PeriodType,
+    type DisabledDate,
+    type SelectedDate,
+    startOfInterval,
+  } from '@layerstack/utils';
 
   import Month from './Month.svelte';
   import MonthListByYear from './MonthListByYear.svelte';
@@ -20,7 +24,10 @@
   export let disabledDates: DisabledDate | undefined = undefined;
 
   // @ts-expect-error
-  $: startOfMonth = selected?.[activeDate] ? startOfMonthFunc(selected[activeDate]) : undefined;
+  $: startOfMonth = selected?.[activeDate]
+    ? // @ts-expect-error
+      startOfInterval('month', selected[activeDate])
+    : undefined;
 </script>
 
 {#if periodType === PeriodType.Month || periodType === PeriodType.Quarter}

diff --git a/packages/svelte-ux/src/lib/components/Month.svelte b/packages/svelte-ux/src/lib/components/Month.svelte
@@ -1,15 +1,13 @@
 <script lang="ts">
   import {
-    startOfDay as startOfDayFunc,
-    endOfDay as endOfDayFunc,
-    startOfMonth as startOfMonthFunc,
-    endOfMonth as endOfMonthFunc,
-    addMonths,
-    isSameDay,
-    isWithinInterval,
-  } from 'date-fns';
-  import { type SelectedDate, PeriodType, hasKeyOf } from '@layerstack/utils';
-  import { getMonthDaysByWeek } from '@layerstack/utils/date';
+    type SelectedDate,
+    PeriodType,
+    hasKeyOf,
+    startOfInterval,
+    endOfInterval,
+    intervalOffset,
+  } from '@layerstack/utils';
+  import { getMonthDaysByWeek, isDateWithin, isSameInterval } from '@layerstack/utils/date';
 
   import { mdiChevronLeft, mdiChevronRight } from '@mdi/js';
 
@@ -21,18 +19,18 @@
   export let selected: SelectedDate = undefined;
 
   export let startOfMonth =
-    (selected instanceof Date && startOfMonthFunc(selected)) ||
-    (selected instanceof Array && selected.length && startOfMonthFunc(selected[0])) ||
+    (selected instanceof Date && startOfInterval('month', selected)) ||
+    (selected instanceof Array && selected.length && startOfInterval('month', selected[0])) ||
     (selected &&
       hasKeyOf<{ from: Date }>(selected, 'from') &&
       selected.from &&
-      startOfMonthFunc(selected.from)) ||
-    startOfMonthFunc(new Date());
+      startOfInterval('month', selected.from)) ||
+    startOfInterval('month', new Date());
 
   const { format } = getSettings();
   $: dateFormat = $format.settings.formats.dates;
 
-  $: endOfMonth = endOfMonthFunc(startOfMonth);
+  $: endOfMonth = endOfInterval('month', startOfMonth);
   $: monthDaysByWeek = getMonthDaysByWeek(startOfMonth, dateFormat.weekStartsOn);
 
   /**
@@ -56,27 +54,27 @@
     return disabledDates instanceof Function
       ? disabledDates(date)
       : disabledDates instanceof Date
-        ? isSameDay(date, disabledDates)
+        ? isSameInterval('day', date, disabledDates)
         : disabledDates instanceof Array
-          ? disabledDates.some((d) => isSameDay(date, d))
+          ? disabledDates.some((d) => isSameInterval('day', date, d))
           : disabledDates instanceof Object
-            ? isWithinInterval(date, {
-                start: startOfDayFunc(disabledDates.from),
-                end: endOfDayFunc(disabledDates.to || disabledDates.from),
+            ? isDateWithin(date, {
+                start: startOfInterval('day', disabledDates.from),
+                end: endOfInterval('day', disabledDates.to || disabledDates.from),
               })
             : false;
   };
 
   $: isDayHidden = (day: Date) => {
-    const isCurrentMonth = isWithinInterval(day, {
+    const isCurrentMonth = isDateWithin(day, {
       start: startOfMonth,
       end: endOfMonth,
     });
     return !isCurrentMonth && !showOutsideDays;
   };
 
   $: isDayFaded = (day: Date) => {
-    const isCurrentMonth = isWithinInterval(day, {
+    const isCurrentMonth = isDateWithin(day, {
       start: startOfMonth,
       end: endOfMonth,
     });
@@ -102,7 +100,7 @@
       <Button
         icon={mdiChevronLeft}
         class="p-2"
-        on:click={() => (startOfMonth = addMonths(startOfMonth, -1))}
+        on:click={() => (startOfMonth = intervalOffset('month', startOfMonth, -1))}
       />
 
       <div class="flex flex-1 items-center justify-center">
@@ -114,7 +112,7 @@
       <Button
         icon={mdiChevronRight}
         class="p-2"
-        on:click={() => (startOfMonth = addMonths(startOfMonth, 1))}
+        on:click={() => (startOfMonth = intervalOffset('month', startOfMonth, 1))}
       />
     </div>
   {/if}

diff --git a/packages/svelte-ux/src/lib/components/MonthList.svelte b/packages/svelte-ux/src/lib/components/MonthList.svelte
@@ -1,7 +1,14 @@
 <script lang="ts">
   import type { ComponentProps } from 'svelte';
-  import { isSameMonth, isWithinInterval, startOfMonth, endOfMonth } from 'date-fns';
-  import { type DisabledDate, type SelectedDate, PeriodType } from '@layerstack/utils';
+  import {
+    type DisabledDate,
+    type SelectedDate,
+    PeriodType,
+    isSameInterval,
+    startOfInterval,
+    endOfInterval,
+    isDateWithin,
+  } from '@layerstack/utils';
   import { getMonths } from '@layerstack/utils/date';
 
   import DateButton from './DateButton.svelte';
@@ -18,13 +25,13 @@
     return disabledDates instanceof Function
       ? disabledDates(date)
       : disabledDates instanceof Date
-        ? isSameMonth(date, disabledDates)
+        ? isSameInterval('month', date, disabledDates)
         : disabledDates instanceof Array
-          ? disabledDates.some((d) => isSameMonth(date, d))
+          ? disabledDates.some((d) => isSameInterval('month', date, d))
           : disabledDates instanceof Object
-            ? isWithinInterval(date, {
-                start: startOfMonth(disabledDates.from),
-                end: endOfMonth(disabledDates.to || disabledDates.from),
+            ? isDateWithin(date, {
+                start: startOfInterval('month', disabledDates.from),
+                end: endOfInterval('month', disabledDates.to || disabledDates.from),
               })
             : false;
   };

diff --git a/packages/svelte-ux/src/lib/components/MonthListByYear.svelte b/packages/svelte-ux/src/lib/components/MonthListByYear.svelte
@@ -1,7 +1,6 @@
 <script lang="ts">
-  import { addYears, subYears } from 'date-fns';
   import { getMinSelectedDate, getMaxSelectedDate } from '@layerstack/utils/date';
-  import type { SelectedDate } from '@layerstack/utils';
+  import { intervalOffset, type SelectedDate } from '@layerstack/utils';
 
   import Button from './Button.svelte';
   import MonthList from './MonthList.svelte';
@@ -15,14 +14,14 @@
     minYear ??
     (minDate
       ? minDate.getFullYear()
-      : subYears(getMinSelectedDate(selected) || new Date(), 2).getFullYear());
+      : intervalOffset('year', getMinSelectedDate(selected) || new Date(), -2).getFullYear());
 
   let maxYear: number;
   $: maxYear =
     maxYear ??
     (maxDate
       ? maxDate.getFullYear()
-      : addYears(getMaxSelectedDate(selected) || new Date(), 2).getFullYear());
+      : intervalOffset('year', getMaxSelectedDate(selected) || new Date(), 2).getFullYear());
 
   $: years = Array.from({ length: maxYear - minYear + 1 }, (_, i) => minYear + i);
 

diff --git a/packages/svelte-ux/src/lib/components/YearList.svelte b/packages/svelte-ux/src/lib/components/YearList.svelte
@@ -1,14 +1,15 @@
 <script lang="ts">
   import type { ComponentProps } from 'svelte';
   import {
-    addYears,
-    subYears,
-    isSameYear,
-    isWithinInterval,
-    startOfYear,
-    endOfYear,
-  } from 'date-fns';
-  import { type DisabledDate, type SelectedDate, PeriodType } from '@layerstack/utils';
+    type DisabledDate,
+    type SelectedDate,
+    PeriodType,
+    intervalOffset,
+    isSameInterval,
+    startOfInterval,
+    endOfInterval,
+    isDateWithin,
+  } from '@layerstack/utils';
   import { getMinSelectedDate, getMaxSelectedDate } from '@layerstack/utils/date';
 
   import Button from './Button.svelte';
@@ -29,14 +30,14 @@
     minYear ??
     (minDate
       ? minDate.getFullYear()
-      : subYears(getMinSelectedDate(selected) || new Date(), 2).getFullYear());
+      : intervalOffset('year', getMinSelectedDate(selected) || new Date(), -2).getFullYear());
 
   let maxYear: number;
   $: maxYear =
     maxYear ??
     (maxDate
       ? maxDate.getFullYear()
-      : addYears(getMaxSelectedDate(selected) || new Date(), 2).getFullYear());
+      : intervalOffset('year', getMaxSelectedDate(selected) || new Date(), 2).getFullYear());
 
   $: years = Array.from({ length: maxYear - minYear + 1 }, (_, i) => minYear + i) ?? [];
 
@@ -47,13 +48,13 @@
     return disabledDates instanceof Function
       ? disabledDates(date)
       : disabledDates instanceof Date
-        ? isSameYear(date, disabledDates)
+        ? isSameInterval('year', date, disabledDates)
         : disabledDates instanceof Array
-          ? disabledDates.some((d) => isSameYear(date, d))
+          ? disabledDates.some((d) => isSameInterval('year', date, d))
           : disabledDates instanceof Object
-            ? isWithinInterval(date, {
-                start: startOfYear(disabledDates.from),
-                end: endOfYear(disabledDates.to || disabledDates.from),
+            ? isDateWithin(date, {
+                start: startOfInterval('year', disabledDates.from),
+                end: endOfInterval('year', disabledDates.to || disabledDates.from),
               })
             : false;
   };

diff --git a/packages/svelte-ux/src/routes/docs/components/DateField/+page.svelte b/packages/svelte-ux/src/routes/docs/components/DateField/+page.svelte
@@ -1,8 +1,8 @@
 <script lang="ts">
-  import { addDays } from 'date-fns';
+  import { Button, DateField, getSettings } from 'svelte-ux';
   import { mdiCalendarStart, mdiCalendarEnd } from '@mdi/js';
+  import { intervalOffset } from '@layerstack/utils';
 
-  import { Button, DateField, getSettings } from 'svelte-ux';
   import Preview from '$lib/components/Preview.svelte';
 
   const { localeSettings } = getSettings();
@@ -32,13 +32,13 @@
   <Button on:click={() => (value = new Date())}>
     {$localeSettings.dictionary.Date.PeriodDay.Current}
   </Button>
-  <Button on:click={() => (value = addDays(new Date(), -1))}>
+  <Button on:click={() => (value = intervalOffset('day', new Date(), -1))}>
     {$localeSettings.dictionary.Date.PeriodDay.Last}
   </Button>
-  <Button on:click={() => (value = addDays(new Date(), -7))}>
+  <Button on:click={() => (value = intervalOffset('day', new Date(), -7))}>
     {$localeSettings.dictionary.Date.PeriodWeek.Last}
   </Button>
-  <Button on:click={() => (value = addDays(new Date(), 7))}>
+  <Button on:click={() => (value = intervalOffset('day', new Date(), 7))}>
     <!-- TODO: Add to dictionary -->
     Next week
   </Button>