diff --git a/changelog/27379.txt b/changelog/27379.txt
new file mode 100644
index 000000000000..1744873c2839
--- /dev/null
+++ b/changelog/27379.txt
@@ -0,0 +1,5 @@
+```release-note:change
+activity: The startTime will be set to the start of the current billing period by default.
+The endTime will be set to the end of the current month. This applies to /sys/internal/counters/activity,
+/sys/internal/counters/activity/export, and the vault operator usage command that utilizes /sys/internal/counters/activity.
+```
diff --git a/command/operator_usage.go b/command/operator_usage.go
index 079ddaba8fbc..117b3b78e018 100644
--- a/command/operator_usage.go
+++ b/command/operator_usage.go
@@ -56,7 +56,7 @@ func (c *OperatorUsageCommand) Flags() *FlagSets {
 
 	f.TimeVar(&TimeVar{
 		Name:       "start-time",
-		Usage:      "Start of report period. Defaults to 'default_reporting_period' before end time.",
+		Usage:      "Start of report period. Defaults to billing start time",
 		Target:     &c.flagStartTime,
 		Completion: complete.PredictNothing,
 		Default:    time.Time{},
@@ -64,7 +64,7 @@ func (c *OperatorUsageCommand) Flags() *FlagSets {
 	})
 	f.TimeVar(&TimeVar{
 		Name:       "end-time",
-		Usage:      "End of report period. Defaults to end of last month.",
+		Usage:      "End of report period. Defaults to end of the current month.",
 		Target:     &c.flagEndTime,
 		Completion: complete.PredictNothing,
 		Default:    time.Time{},
diff --git a/vault/external_tests/activity/activity_util.go b/vault/external_tests/activity/activity_util.go
new file mode 100644
index 000000000000..499eb46ff33c
--- /dev/null
+++ b/vault/external_tests/activity/activity_util.go
@@ -0,0 +1,48 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+package activity
+
+import (
+	"testing"
+	"time"
+
+	"github.com/hashicorp/vault/api"
+	"github.com/hashicorp/vault/vault"
+	"github.com/mitchellh/mapstructure"
+)
+
+type QueryResponse struct {
+	StartTime   string                     `json:"start_time" mapstructure:"start_time"`
+	EndTime     string                     `json:"end_time" mapstructure:"end_time"`
+	ByNamespace []*vault.ResponseNamespace `json:"by_namespace"`
+	Total       *vault.ResponseCounts      `json:"total"`
+}
+
+func expectEndTime(t *testing.T, expected time.Time, resp *api.Secret) {
+	t.Helper()
+
+	qr := QueryResponse{}
+	mapstructure.Decode(resp.Data, &qr)
+	parsedTime, err := time.Parse(time.RFC3339, qr.EndTime)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !expected.Equal(parsedTime) {
+		t.Errorf("wrong end time, expected %v actual %v", expected, parsedTime)
+	}
+}
+
+func expectStartTime(t *testing.T, expected time.Time, resp *api.Secret) {
+	t.Helper()
+
+	var qr QueryResponse
+	mapstructure.Decode(resp.Data, &qr)
+	parsedTime, err := time.Parse(time.RFC3339, qr.StartTime)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !expected.Equal(parsedTime) {
+		t.Errorf("wrong start time, expected %v actual %v", expected, parsedTime)
+	}
+}
diff --git a/vault/logical_system_activity.go b/vault/logical_system_activity.go
index c286b572d07d..f7607a191cd0 100644
--- a/vault/logical_system_activity.go
+++ b/vault/logical_system_activity.go
@@ -13,7 +13,6 @@ import (
 	"time"
 
 	"github.com/hashicorp/go-secure-stdlib/parseutil"
-	"github.com/hashicorp/vault/helper/timeutil"
 	"github.com/hashicorp/vault/sdk/framework"
 	"github.com/hashicorp/vault/sdk/logical"
 )
@@ -182,23 +181,25 @@ func (b *SystemBackend) rootActivityPaths() []*framework.Path {
 	return paths
 }
 
-func parseStartEndTimes(a *ActivityLog, d *framework.FieldData) (time.Time, time.Time, error) {
+func parseStartEndTimes(a *ActivityLog, d *framework.FieldData, billingStartTime time.Time) (time.Time, time.Time, error) {
 	startTime := d.Get("start_time").(time.Time)
 	endTime := d.Get("end_time").(time.Time)
 
 	// If a specific endTime is used, then respect that
-	// otherwise we want to give the latest N months, so go back to the start
-	// of the previous month
+	// otherwise we want to query up until the end of the current month.
 	//
 	// Also convert any user inputs to UTC to avoid
 	// problems later.
 	if endTime.IsZero() {
-		endTime = timeutil.EndOfMonth(timeutil.StartOfPreviousMonth(time.Now().UTC()))
+		endTime = time.Now().UTC()
 	} else {
 		endTime = endTime.UTC()
 	}
+
+	// If startTime is not specified, we would like to query
+	// from the beginning of the billing period
 	if startTime.IsZero() {
-		startTime = a.DefaultStartTime(endTime)
+		startTime = billingStartTime
 	} else {
 		startTime = startTime.UTC()
 	}
@@ -218,7 +219,7 @@ func (b *SystemBackend) handleClientExport(ctx context.Context, req *logical.Req
 		return logical.ErrorResponse("no activity log present"), nil
 	}
 
-	startTime, endTime, err := parseStartEndTimes(a, d)
+	startTime, endTime, err := parseStartEndTimes(a, d, b.Core.BillingStart())
 	if err != nil {
 		return logical.ErrorResponse(err.Error()), nil
 	}
@@ -257,7 +258,7 @@ func (b *SystemBackend) handleClientMetricQuery(ctx context.Context, req *logica
 		endTime = time.Now().UTC()
 	} else {
 		var err error
-		startTime, endTime, err = parseStartEndTimes(a, d)
+		startTime, endTime, err = parseStartEndTimes(a, d, b.Core.BillingStart())
 		if err != nil {
 			return logical.ErrorResponse(err.Error()), nil
 		}