diff --git a/src/datatypes/timeRange.ts b/src/datatypes/timeRange.ts
index ca2dd744..f3ef441d 100644
--- a/src/datatypes/timeRange.ts
+++ b/src/datatypes/timeRange.ts
@@ -68,13 +68,18 @@ export class TimeRange extends Range<Date> implements Instance<TimeRangeValue, T
     return dateToIntervalPart(date) + '/' + dateToIntervalPart(new Date(date.valueOf() + 1));
   }
 
-  static timeBucket(date: Date, duration: Duration, timezone: Timezone): TimeRange {
+  static timeBucket(
+    date: Date,
+    duration: Duration,
+    timezone: Timezone,
+    bounds?: string,
+  ): TimeRange {
     if (!date) return null;
     const start = duration.floor(date, timezone);
     return new TimeRange({
       start: start,
       end: duration.shift(start, timezone, 1),
-      bounds: Range.DEFAULT_BOUNDS,
+      bounds: bounds ?? Range.DEFAULT_BOUNDS,
     });
   }
 
@@ -183,6 +188,12 @@ export class TimeRange extends Range<Date> implements Instance<TimeRangeValue, T
     });
   }
 
+  public changeBounds(bounds: string): TimeRange {
+    const value = this.toJS();
+    value.bounds = bounds;
+    return TimeRange.fromJS(value);
+  }
+
   public shift(duration: Duration, timezone: Timezone, step?: number): TimeRange {
     const { start, end, bounds } = this;
     if (!start) return this;
diff --git a/src/expressions/timeBucketExpression.ts b/src/expressions/timeBucketExpression.ts
index e10225f3..d9d49295 100644
--- a/src/expressions/timeBucketExpression.ts
+++ b/src/expressions/timeBucketExpression.ts
@@ -30,17 +30,19 @@ export class TimeBucketExpression extends ChainableExpression {
     const value = ChainableExpression.jsToValue(parameters);
     value.duration = Duration.fromJS(parameters.duration);
     if (parameters.timezone) value.timezone = Timezone.fromJS(parameters.timezone);
+    if (parameters.bounds) value.bounds = parameters.bounds;
     return new TimeBucketExpression(value);
   }
 
   public duration: Duration;
   public timezone: Timezone;
-
+  public bounds: string;
   constructor(parameters: ExpressionValue) {
     super(parameters, dummyObject);
     const duration = parameters.duration;
     this.duration = duration;
     this.timezone = parameters.timezone;
+    this.bounds = parameters.bounds;
     this._ensureOp('timeBucket');
     this._checkOperandTypes('TIME');
     if (!(duration instanceof Duration)) {
@@ -55,6 +57,7 @@ export class TimeBucketExpression extends ChainableExpression {
   public valueOf(): ExpressionValue {
     const value = super.valueOf();
     value.duration = this.duration;
+    value.bounds = this.bounds;
     if (this.timezone) value.timezone = this.timezone;
     return value;
   }
@@ -62,6 +65,7 @@ export class TimeBucketExpression extends ChainableExpression {
   public toJS(): ExpressionJS {
     const js = super.toJS();
     js.duration = this.duration.toJS();
+    if (this.bounds) js.bounds = this.bounds;
     if (this.timezone) js.timezone = this.timezone.toJS();
     return js;
   }
@@ -70,6 +74,7 @@ export class TimeBucketExpression extends ChainableExpression {
     return (
       super.equals(other) &&
       this.duration.equals(other.duration) &&
+      this.bounds === other.bounds &&
       immutableEqual(this.timezone, other.timezone)
     );
   }
@@ -77,12 +82,13 @@ export class TimeBucketExpression extends ChainableExpression {
   protected _toStringParameters(_indent?: int): string[] {
     const ret = [this.duration.toString()];
     if (this.timezone) ret.push(Expression.safeString(this.timezone.toString()));
+    if (this.bounds) ret.push(this.bounds);
     return ret;
   }
 
   protected _calcChainableHelper(operandValue: any): PlywoodValue {
     return operandValue
-      ? TimeRange.timeBucket(operandValue, this.duration, this.getTimezone())
+      ? TimeRange.timeBucket(operandValue, this.duration, this.getTimezone(), this.bounds)
       : null;
   }
 
@@ -90,6 +96,12 @@ export class TimeBucketExpression extends ChainableExpression {
     return dialect.timeBucketExpression(operandSQL, this.duration, this.getTimezone());
   }
 
+  public changeBounds(bounds: string): Expression {
+    const value = this.valueOf();
+    value.bounds = bounds;
+    return Expression.fromValue(value);
+  }
+
   // HasTimezone mixin:
   public getTimezone: () => Timezone;
   public changeTimezone: (timezone: Timezone) => this;
diff --git a/src/expressions/timeRangeExpression.ts b/src/expressions/timeRangeExpression.ts
index 3bdf6b19..d41ff782 100644
--- a/src/expressions/timeRangeExpression.ts
+++ b/src/expressions/timeRangeExpression.ts
@@ -33,6 +33,7 @@ export class TimeRangeExpression extends ChainableExpression implements HasTimez
     const value = ChainableExpression.jsToValue(parameters);
     value.duration = Duration.fromJS(parameters.duration);
     value.step = parameters.step;
+    value.bounds = parameters.bounds;
     if (parameters.timezone) value.timezone = Timezone.fromJS(parameters.timezone);
     return new TimeRangeExpression(value);
   }
@@ -114,11 +115,15 @@ export class TimeRangeExpression extends ChainableExpression implements HasTimez
     throw new Error('implement me');
   }
 
+  public changeBounds(bounds: string): Expression {
+    const value = this.valueOf();
+    value.bounds = bounds;
+    return Expression.fromValue(value);
+  }
+
   // HasTimezone mixin:
   public getTimezone: () => Timezone;
   public changeTimezone: (timezone: Timezone) => TimeRangeExpression;
-  public getBounds: () => String;
-  public changeBounds: (bounds: String) => TimeRangeExpression;
 }
 
 Expression.applyMixins(TimeRangeExpression, [HasTimezone]);