diff --git a/v3/src/components/slider/slider-model.ts b/v3/src/components/slider/slider-model.ts
index de33f5c57..46c4dd85e 100644
--- a/v3/src/components/slider/slider-model.ts
+++ b/v3/src/components/slider/slider-model.ts
@@ -8,9 +8,11 @@ import { getGlobalValueManager, getSharedModelManager } from "../../models/tiles
 import { ITileContentModel, TileContentModel } from "../../models/tiles/tile-content"
 import { DateUnit, dateUnits, unitsStringToMilliseconds } from "../../utilities/date-utils"
 import { kSliderTileType } from "./slider-defs"
-import {AnimationDirection, AnimationDirections, AnimationMode, AnimationModes, FixValueFn, ISliderScaleType,
+import {
+  AnimationDirection, AnimationDirections, AnimationMode, AnimationModes, FixValueFn, ISliderScaleType,
   kDefaultAnimationDirection, kDefaultAnimationMode, kDefaultAnimationRate, kDefaultDateMultipleOfUnit,
-  kDefaultSliderScaleType, SliderScaleTypes} from "./slider-types"
+  kDefaultSliderAxisMax, kDefaultSliderAxisMin, kDefaultSliderScaleType, SliderScaleTypes
+} from "./slider-types"
 
 export const SliderModel = TileContentModel
   .named("SliderModel")
@@ -25,7 +27,7 @@ export const SliderModel = TileContentModel
     _animationRate: types.maybe(types.number),  // frames per second
     scaleType: types.optional(types.enumeration([...SliderScaleTypes]), kDefaultSliderScaleType),
     axis: types.optional(types.union(NumericAxisModel, DateAxisModel),
-      () => NumericAxisModel.create({ place: 'bottom', min: -0.5, max: 11.5 }))
+      () => NumericAxisModel.create({ place: 'bottom', min: kDefaultSliderAxisMin, max: kDefaultSliderAxisMax }))
   })
   .views(self => ({
     get name() {
@@ -169,7 +171,8 @@ export const SliderModel = TileContentModel
       if (scaleType !== self.scaleType) {
         switch (scaleType) {
           case "numeric":
-            self.axis = NumericAxisModel.create({ place: 'bottom', min: -0.5, max: 11.5 })
+            self.axis = NumericAxisModel.create({
+                          place: 'bottom', min: kDefaultSliderAxisMin, max: kDefaultSliderAxisMax })
             self.setValue(0.5)
             break
           case "date": {
diff --git a/v3/src/components/slider/slider-registration.test.ts b/v3/src/components/slider/slider-registration.test.ts
index 97b149226..b95b077be 100644
--- a/v3/src/components/slider/slider-registration.test.ts
+++ b/v3/src/components/slider/slider-registration.test.ts
@@ -85,6 +85,7 @@ describe("Slider registration", () => {
     })
     expect(tileWithNoSharedModel).toBeUndefined()
 
+    // export numeric slider in v2 format
     const row = docContent.getRowByIndex(0) as IFreeTileRow
     const sliderExport = exportV2Component({ tile, row, sharedModelManager })
     expect(sliderExport?.type).toBe("DG.SliderView")
@@ -94,5 +95,19 @@ describe("Slider registration", () => {
     expect(sliderStorage.animationMode).toBe(1)
     expect(sliderStorage.maxPerSecond).toBeNull()
     expect(sliderStorage.restrictToMultiplesOf).toBeNull()
+
+    // change to date-time slider and export in v2 format
+    sliderModel!.setScaleType("date")
+    sliderModel!.setDateMultipleOfUnit("day")
+    const dateSliderExport = exportV2Component({ tile, row, sharedModelManager })
+    expect(dateSliderExport?.type).toBe("DG.SliderView")
+    const dateSliderStorage = dateSliderExport!.componentStorage as ICodapV2SliderStorage
+    expect(dateSliderStorage._links_?.model).toBeDefined()
+    expect(dateSliderStorage.animationDirection).toBe(1)
+    expect(dateSliderStorage.animationMode).toBe(1)
+    expect(dateSliderStorage.maxPerSecond).toBeNull()
+    expect(dateSliderStorage.restrictToMultiplesOf).toBeNull()
+    expect(dateSliderStorage.v3?.scaleType).toBe("date")
+    expect(dateSliderStorage.v3?.dateMultipleOfUnit).toBe("day")
   })
 })
diff --git a/v3/src/components/slider/slider-registration.ts b/v3/src/components/slider/slider-registration.ts
index a3c7c3c24..869631008 100644
--- a/v3/src/components/slider/slider-registration.ts
+++ b/v3/src/components/slider/slider-registration.ts
@@ -10,6 +10,7 @@ import { ITileLikeModel, registerTileContentInfo } from "../../models/tiles/tile
 import { getGlobalValueManager } from "../../models/tiles/tile-environment"
 import { ITileModelSnapshotIn } from "../../models/tiles/tile-model"
 import { toV2Id, toV3GlobalId, toV3Id } from "../../utilities/codap-utils"
+import { DateUnit, unitsStringToMilliseconds } from "../../utilities/date-utils"
 import { isFiniteNumber } from "../../utilities/math-utils"
 import { isAliveSafe } from "../../utilities/mst-utils"
 import { t } from "../../utilities/translation/translate"
@@ -25,7 +26,7 @@ import { ISliderSnapshot, SliderModel, isSliderModel } from "./slider-model"
 import { SliderTitleBar } from "./slider-title-bar"
 import {
   AnimationDirection, AnimationDirections, AnimationMode, AnimationModes,
-  kDefaultAnimationDirection, kDefaultAnimationMode
+  kDefaultAnimationDirection, kDefaultAnimationMode, kDefaultSliderAxisMax, kDefaultSliderAxisMin
 } from "./slider-types"
 import { kDefaultSliderName, kDefaultSliderValue } from "./slider-utils"
 
@@ -74,7 +75,7 @@ registerTileComponentInfo({
   defaultHeight: 73
 })
 
-registerV2TileExporter((kSliderTileType), ({ tile }) => {
+registerV2TileExporter(kSliderTileType, ({ tile }) => {
   const sliderModel = isSliderModel(tile.content) ? tile.content : undefined
   if (!sliderModel) return
   const {
@@ -82,7 +83,9 @@ registerV2TileExporter((kSliderTileType), ({ tile }) => {
     animationDirection,
     animationMode,
     _animationRate,
-    multipleOf
+    multipleOf,
+    dateMultipleOfUnit,
+    scaleType
   } = sliderModel
 
   const domain = isFiniteNumber(lowerBound) && isFiniteNumber(upperBound) ? { lowerBound, upperBound } : undefined
@@ -93,6 +96,12 @@ registerV2TileExporter((kSliderTileType), ({ tile }) => {
   const getAnimationModeIndex = (mode?: AnimationMode) => {
     return mode != null ? AnimationModes.findIndex(_mode => _mode === mode) : 1
   }
+  // v2 doesn't support date-time sliders; convert to seconds instead
+  const restrictToMultiplesOf = scaleType === "date" && multipleOf != null
+                                  ? multipleOf * unitsStringToMilliseconds(dateMultipleOfUnit) / 1000
+                                  : multipleOf
+  // v3 extensions: ignored by v2, but allows full round-trip for v3 save/restore
+  const v3: ICodapV2SliderStorage["v3"] = { scaleType, multipleOf, dateMultipleOfUnit }
 
   const componentStorage: SetOptional<ICodapV2SliderStorage, keyof ICodapV2BaseComponentStorage> = {
     _links_: { model: guidLink("DG.GlobalValue", toV2Id(tile.id)) },
@@ -100,7 +109,8 @@ registerV2TileExporter((kSliderTileType), ({ tile }) => {
     animationDirection: getAnimationDirectionIndex(animationDirection),
     animationMode: getAnimationModeIndex(animationMode),
     maxPerSecond: _animationRate ?? null,
-    restrictToMultiplesOf: multipleOf ?? null
+    restrictToMultiplesOf: restrictToMultiplesOf ?? null,
+    v3
   }
   return { type: "DG.SliderView", componentStorage }
 })
@@ -116,7 +126,7 @@ registerV2TileImporter("DG.SliderView", ({ v2Component, v2Document, sharedModelM
     guid: componentGuid,
     componentStorage: {
       name, title: v2Title = "", _links_, lowerBound, upperBound, animationDirection, animationMode,
-      restrictToMultiplesOf, maxPerSecond, userTitle, userSetTitle
+      restrictToMultiplesOf, maxPerSecond, userTitle, userSetTitle, v3
     }
   } = v2Component
   const globalId = _links_.model.id
@@ -137,15 +147,20 @@ registerV2TileImporter("DG.SliderView", ({ v2Component, v2Document, sharedModelM
     return AnimationModes[mode] || kDefaultAnimationMode
   }
 
+  const axisType = v3?.scaleType ?? "numeric"
+  const axisMin = lowerBound ?? kDefaultSliderAxisMin
+  const axisMax = upperBound ?? kDefaultSliderAxisMax
+
   // create slider model
   const content: ISliderSnapshot = {
     type: kSliderTileType,
     globalValue: globalValue.id,
-    multipleOf: restrictToMultiplesOf ?? undefined,
+    multipleOf: v3?.multipleOf ?? restrictToMultiplesOf ?? undefined,
+    dateMultipleOfUnit: v3?.dateMultipleOfUnit as DateUnit ?? undefined,
     animationDirection: getAnimationDirectionStr(animationDirection),
     animationMode: getAnimationModeStr(animationMode),
     _animationRate: maxPerSecond ?? undefined,
-    axis: { type: "numeric", place: "bottom", min: lowerBound ?? 0, max: upperBound ?? 12 }
+    axis: { type: axisType, place: "bottom", min: axisMin, max: axisMax }
   }
   const title = v2Title && (userTitle || userSetTitle) ? v2Title : undefined
   const sliderTileSnap: ITileModelSnapshotIn = {
diff --git a/v3/src/components/slider/slider-types.ts b/v3/src/components/slider/slider-types.ts
index daef3fcdb..b07d1c99a 100644
--- a/v3/src/components/slider/slider-types.ts
+++ b/v3/src/components/slider/slider-types.ts
@@ -9,6 +9,9 @@ export const kDefaultSliderAxisTop = 0
 export const kDefaultSliderAxisHeight = 24
 export const kDefaultSliderPadding = 10
 
+export const kDefaultSliderAxisMin = -0.5
+export const kDefaultSliderAxisMax = 11.5
+
 // values are translation string keys; indices are v2 values
 export const AnimationDirections = ["backAndForth", "lowToHigh", "highToLow"] as const
 export type AnimationDirection = typeof AnimationDirections[number]
diff --git a/v3/src/v2/codap-v2-types.ts b/v3/src/v2/codap-v2-types.ts
index f6bae635f..43a7b9c5d 100644
--- a/v3/src/v2/codap-v2-types.ts
+++ b/v3/src/v2/codap-v2-types.ts
@@ -245,6 +245,8 @@ export interface ICodapV2BaseComponentStorage {
   // In the CFM shared files there are more than 20,000 examples of cannotClose: true
   // and more 20,000 examples cannotClose: false
   cannotClose?: boolean
+  // allows v2 documents saved by v3 to contain v3-specific enhancements
+  v3?: object
 }
 
 export interface ICodapV2CalculatorStorage extends ICodapV2BaseComponentStorage {
@@ -264,6 +266,12 @@ export interface ICodapV2SliderStorage extends ICodapV2BaseComponentStorage {
   // NOTE: v2 writes out the `userTitle` property, but reads in property `userChangedTitle`.
   // It is also redundant with the `userSetTitle` property shared by all components. ¯\_(ツ)_/¯
   userTitle?: boolean
+  // v3 enhancements
+  v3?: {
+    scaleType: "numeric" | "date",
+    multipleOf?: number
+    dateMultipleOfUnit?: string
+  }
 }
 
 export interface ICodapV2RowHeight {