diff --git a/tools/cli/internal/changelog/changelog.go b/tools/cli/internal/changelog/changelog.go
index da0dc13c24..91a5a97292 100644
--- a/tools/cli/internal/changelog/changelog.go
+++ b/tools/cli/internal/changelog/changelog.go
@@ -108,6 +108,11 @@ type Change struct {
 // The returned entries includes all the changes between the base and revision specs included the one
 // marked as hidden.
 func NewEntries(basePath, revisionPath, exceptionFilePath string) ([]*Entry, error) {
+	return NewEntriesWithRunDate(basePath, revisionPath, exceptionFilePath, time.Now().Format("2006-01-02"))
+}
+
+// NewEntriesWithRunDate generates the changelog entries with a specific run date.
+func NewEntriesWithRunDate(basePath, revisionPath, exceptionFilePath, runDate string) ([]*Entry, error) {
 	baseMetadata, err := newMetadataFromFile(basePath)
 	if err != nil {
 		return nil, err
@@ -120,7 +125,7 @@ func NewEntries(basePath, revisionPath, exceptionFilePath string) ([]*Entry, err
 	}
 	log.Printf("Revision Metadata: %s", newStringFromStruct(revisionMetadata))
 
-	revisionMetadata.RunDate = time.Now().Format("2006-01-02")
+	revisionMetadata.RunDate = runDate
 
 	baseActiveVersionOnPreviousRunDate, err := latestVersionActiveOnDate(baseMetadata.RunDate, baseMetadata.Versions)
 	if err != nil {
@@ -208,7 +213,12 @@ func NewEntries(basePath, revisionPath, exceptionFilePath string) ([]*Entry, err
 // The returned entries includes the changes between the base and revision specs that are not
 // marked as hidden.
 func NewEntriesWithoutHidden(basePath, revisionPath, exceptionFilePath string) ([]*Entry, error) {
-	entries, err := NewEntries(basePath, revisionPath, exceptionFilePath)
+	return NewEntriesWithoutHiddenWithRunDate(basePath, revisionPath, exceptionFilePath, time.Now().Format("2006-01-02"))
+}
+
+// NewEntriesWithoutHiddenWithRunDate generates the changelog entries with a specific run date.
+func NewEntriesWithoutHiddenWithRunDate(basePath, revisionPath, exceptionFilePath, runDate string) ([]*Entry, error) {
+	entries, err := NewEntriesWithRunDate(basePath, revisionPath, exceptionFilePath, runDate)
 	if err != nil {
 		return nil, err
 	}
@@ -218,6 +228,11 @@ func NewEntriesWithoutHidden(basePath, revisionPath, exceptionFilePath string) (
 
 // NewEntriesBetweenRevisionVersions generates the changelog entries between the revision versions.
 func NewEntriesBetweenRevisionVersions(revisionPath, exceptionFilePath string) ([]*Entry, error) {
+	return NewEntriesBetweenRevisionVersionsWithRunDate(revisionPath, exceptionFilePath, time.Now().Format("2006-01-02"))
+}
+
+// NewEntriesBetweenRevisionVersionsWithRunDate generates the changelog entries between the revision versions with a specific run date.
+func NewEntriesBetweenRevisionVersionsWithRunDate(revisionPath, exceptionFilePath, runDate string) ([]*Entry, error) {
 	revisionMetadata, err := newMetadataFromFile(revisionPath)
 	if err != nil {
 		return nil, err
@@ -231,7 +246,7 @@ func NewEntriesBetweenRevisionVersions(revisionPath, exceptionFilePath string) (
 				continue
 			}
 
-			entry, err := newEntriesBetweenVersion(revisionMetadata, fromVersion, toVersion, exceptionFilePath)
+			entry, err := newEntriesBetweenVersionWithRunDate(revisionMetadata, fromVersion, toVersion, exceptionFilePath, runDate)
 			if err != nil {
 				return nil, err
 			}
@@ -242,11 +257,11 @@ func NewEntriesBetweenRevisionVersions(revisionPath, exceptionFilePath string) (
 	return newVersionEntries(entries), nil
 }
 
-func newEntriesBetweenVersion(metadata *Metadata, fromVersion, toVersion, exceptionFilePath string) (*Entry, error) {
+func newEntriesBetweenVersionWithRunDate(metadata *Metadata, fromVersion, toVersion, exceptionFilePath, runDate string) (*Entry, error) {
 	baseMetadata := &Metadata{
 		Path:          metadata.Path,
 		ActiveVersion: fromVersion,
-		RunDate:       time.Now().Format("2006-01-02"),
+		RunDate:       runDate,
 		SpecRevision:  metadata.SpecRevision,
 		Versions:      metadata.Versions,
 	}
@@ -254,7 +269,7 @@ func newEntriesBetweenVersion(metadata *Metadata, fromVersion, toVersion, except
 	revisionMetadata := &Metadata{
 		Path:          metadata.Path,
 		ActiveVersion: toVersion,
-		RunDate:       time.Now().Format("2006-01-02"),
+		RunDate:       runDate,
 		SpecRevision:  metadata.SpecRevision,
 		Versions:      metadata.Versions,
 	}
diff --git a/tools/cli/internal/cli/changelog/create.go b/tools/cli/internal/cli/changelog/create.go
index 98b46b5026..495cfffbff 100644
--- a/tools/cli/internal/cli/changelog/create.go
+++ b/tools/cli/internal/cli/changelog/create.go
@@ -17,6 +17,7 @@ package changelog
 import (
 	"fmt"
 	"log"
+	"time"
 
 	"github.com/mongodb/openapi/tools/cli/internal/changelog"
 	"github.com/mongodb/openapi/tools/cli/internal/cli/flag"
@@ -41,10 +42,20 @@ type Opts struct {
 	exceptionsPaths string
 	outputPath      string
 	dryRun          bool
+	runDate         string
 }
 
 func (o *Opts) Run() error {
-	entries, err := changelog.NewEntries(o.basePath, o.revisionPath, o.exceptionsPaths)
+	runDate := time.Now().Format("2006-01-02")
+	if o.runDate != "" {
+		// Validate the provided run date format
+		if _, err := time.Parse("2006-01-02", o.runDate); err != nil {
+			return fmt.Errorf("invalid run date format: %w. Use YYYY-MM-DD format", err)
+		}
+		runDate = o.runDate
+	}
+
+	entries, err := changelog.NewEntriesWithRunDate(o.basePath, o.revisionPath, o.exceptionsPaths, runDate)
 	if err != nil {
 		return err
 	}
@@ -54,7 +65,7 @@ func (o *Opts) Run() error {
 		return err
 	}
 
-	versionedEntries, err := changelog.NewEntriesBetweenRevisionVersions(o.revisionPath, o.exceptionsPaths)
+	versionedEntries, err := changelog.NewEntriesBetweenRevisionVersionsWithRunDate(o.revisionPath, o.exceptionsPaths, runDate)
 	if err != nil {
 		return err
 	}
@@ -141,6 +152,7 @@ func CreateBuilder() *cobra.Command {
 	cmd.Flags().StringVarP(&opts.exceptionsPaths, flag.ExemptionFilePath, flag.ExemptionFilePathShort, "", usage.ExemptionFilePath)
 	cmd.Flags().BoolVarP(&opts.dryRun, flag.DryRun, flag.DryRunShort, false, usage.DryRun)
 	cmd.Flags().StringVarP(&opts.outputPath, flag.Output, flag.OutputShort, "", usage.Output)
+	cmd.Flags().StringVar(&opts.runDate, "run-date", "", "Fixed run date for testing (YYYY-MM-DD format)")
 
 	_ = cmd.MarkFlagRequired(flag.Base)
 	_ = cmd.MarkFlagRequired(flag.Revision)
diff --git a/tools/cli/test/e2e/cli/changelog_test.go b/tools/cli/test/e2e/cli/changelog_test.go
index befd951bb3..7f457d3eca 100644
--- a/tools/cli/test/e2e/cli/changelog_test.go
+++ b/tools/cli/test/e2e/cli/changelog_test.go
@@ -140,6 +140,8 @@ func TestChangelog(t *testing.T) {
 			exemptions,
 			"-o",
 			commandOut,
+			"--run-date",
+			"2025-06-15", // Fixed date after base run date but before sunset date
 		)
 
 		var o, e bytes.Buffer