diff --git a/go/buscompose/buscompose_test.go b/go/buscompose/buscompose_test.go
index 56d0879..4e1d0d2 100644
--- a/go/buscompose/buscompose_test.go
+++ b/go/buscompose/buscompose_test.go
@@ -659,6 +659,11 @@ func healthChecks(t *testing.T) {
 			t.Errorf("%s writes the assigner's policies", u.Username())
 		}
 	}
+	// 1953 S-age (ADR 0565 §10): a log that says an age keeps its entries that long and no longer; one that says none, as
+	// long as the log (ADR 0297).
+	if aged, kept := (Log{Module: "mesh-hand-acts", Name: "acts", MaxAgeDays: 400}).Config(), (Log{Module: "m", Name: "l"}).Config(); aged.MaxAge != 400*24*time.Hour || kept.MaxAge != 0 || !aged.DenyDelete {
+		t.Errorf("an aged log's stream keeps %s, an unaged one %s", aged.MaxAge, kept.MaxAge)
+	}
 	// The tools account's secret is the module's own broker-<binary>, which its manifest's own-secrets names and the
 	// vault keeps by that name (AccountSecret).
 	if w := (WantedAccount{User: "a.nats.nats-tools", Kind: KindProcess, Node: "a", Module: "nats", Process: "nats-tools",
diff --git a/go/buscompose/log.go b/go/buscompose/log.go
index 5c22001..9f1370f 100644
--- a/go/buscompose/log.go
+++ b/go/buscompose/log.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"sort"
 	"strings"
+	"time"
 
 	"github.com/nats-io/nats.go/jetstream"
 )
@@ -37,6 +38,8 @@ type Log struct {
 	Name   string
 	// MaxMiB is its cap in MiB; zero is LogDefaultMiB.
 	MaxMiB int
+	// MaxAgeDays is how long an entry is kept; zero is as long as the log (catalogue.LogDeclaration).
+	MaxAgeDays int
 }
 
 // LogStreamPrefix starts every log's stream name, which no other stream of the mesh's starts with.
@@ -74,7 +77,7 @@ func (l Log) Why() string {
 }
 
 // Config is the stream a log is, field by field as novox/hq ADR 0297 fixes it: a file stream kept by
-// limits, with no maximum age and no cap per key, whose message is an entry's value and 4 KiB of
+// limits, with no maximum age unless the log says one (ADR 0565 §10) and no cap per key, whose message is an entry's value and 4 KiB of
 // headers at most, that refuses a new entry when full rather than
 // drop an old one, and that refuses deleting an entry or purging it. Direct gets are allowed, which
 // is how the runtime reads it.
@@ -85,7 +88,7 @@ func (l Log) Config() jetstream.StreamConfig {
 		Subjects:          []string{l.Subject() + ".>"},
 		Storage:           jetstream.FileStorage,
 		Retention:         jetstream.LimitsPolicy,
-		MaxAge:            0,
+		MaxAge:            time.Duration(l.MaxAgeDays) * 24 * time.Hour,
 		MaxMsgs:           -1,
 		MaxMsgsPerSubject: -1,
 		MaxBytes:          l.MaxBytes(),
diff --git a/go/catalogue/logs.go b/go/catalogue/logs.go
index 7856b8c..d20aa1c 100644
--- a/go/catalogue/logs.go
+++ b/go/catalogue/logs.go
@@ -27,8 +27,15 @@ type LogDeclaration struct {
 	// MaxMiB is the log's cap in MiB; zero is LogDefaultMiB. When full, the log refuses new entries
 	// and never drops old ones.
 	MaxMiB int `json:"max-mib,omitempty"`
+	// MaxAgeDays is how long an entry is kept, in days; zero is as long as the log (novox/hq ADR 0297). The one way an
+	// entry leaves a log: the server ages it out, never a delete or a purge (novox/hq ADR 0565 §10: the hand-act log
+	// keeps every act 400 days; issue 1953 S-age).
+	MaxAgeDays int `json:"max-age-days,omitempty"`
 }
 
+// LogMostAgeDays is the longest a log may keep an entry by age: past it, a log keeps its entries as long as it is.
+const LogMostAgeDays = 3650
+
 // Cap is the log's cap in MiB, the default where none is said.
 func (l LogDeclaration) Cap() int {
 	if l.MaxMiB == 0 {
@@ -37,20 +44,21 @@ func (l LogDeclaration) Cap() int {
 	return l.MaxMiB
 }
 
-// UnmarshalJSON reads a log as its bare name, or as {name, max-mib}.
+// UnmarshalJSON reads a log as its bare name, or as {name, max-mib, max-age-days}.
 func (l *LogDeclaration) UnmarshalJSON(raw []byte) error {
 	trimmed := bytes.TrimSpace(raw)
 	if len(trimmed) > 0 && trimmed[0] == '"' {
 		return json.Unmarshal(trimmed, &l.Name)
 	}
 	var full struct {
-		Name   string `json:"name"`
-		MaxMiB *int   `json:"max-mib"`
+		Name       string `json:"name"`
+		MaxMiB     *int   `json:"max-mib"`
+		MaxAgeDays *int   `json:"max-age-days"`
 	}
 	dec := json.NewDecoder(bytes.NewReader(trimmed))
 	dec.DisallowUnknownFields()
 	if err := dec.Decode(&full); err != nil {
-		return fmt.Errorf("a log is either a name or {name, max-mib}: %w", typedUnknown(err))
+		return fmt.Errorf("a log is either a name or {name, max-mib, max-age-days}: %w", typedUnknown(err))
 	}
 	l.Name = full.Name
 	l.MaxMiB = 0
@@ -61,12 +69,19 @@ func (l *LogDeclaration) UnmarshalJSON(raw []byte) error {
 		}
 		l.MaxMiB = *full.MaxMiB
 	}
+	l.MaxAgeDays = 0
+	if full.MaxAgeDays != nil {
+		if *full.MaxAgeDays < 1 || *full.MaxAgeDays > LogMostAgeDays {
+			return fmt.Errorf("log %q: max-age-days is between 1 and %d, not %d", full.Name, LogMostAgeDays, *full.MaxAgeDays)
+		}
+		l.MaxAgeDays = *full.MaxAgeDays
+	}
 	return nil
 }
 
 // MarshalJSON writes back the short form when there is nothing else to say.
 func (l LogDeclaration) MarshalJSON() ([]byte, error) {
-	if l.MaxMiB == 0 {
+	if l.MaxMiB == 0 && l.MaxAgeDays == 0 {
 		return json.Marshal(l.Name)
 	}
 	type plain LogDeclaration
diff --git a/go/catalogue/logs_test.go b/go/catalogue/logs_test.go
index 76e7ee0..aeea053 100644
--- a/go/catalogue/logs_test.go
+++ b/go/catalogue/logs_test.go
@@ -24,7 +24,15 @@ func TestAManifestMaySayWhatLogsItKeeps(t *testing.T) {
 	if string(out) != `["changes",{"name":"moves","max-mib":2048}]` {
 		t.Fatalf("written back as %s", out)
 	}
-	for _, edge := range []string{`{"name":"a","max-mib":1}`, `{"name":"a","max-mib":8192}`} {
+	// 1953 S-age (ADR 0565 §10): a log may keep its entries for an age, written back with it.
+	aged, err := ParseManifest([]byte(`{"module":"mesh-hand-acts","version":"1","logs":[{"name":"acts","max-age-days":400}]}`))
+	if err != nil || aged.Logs[0].MaxAgeDays != 400 {
+		t.Fatalf("an aged log read as %+v, %v", aged.Logs, err)
+	}
+	if out, _ := json.Marshal(aged.Logs); string(out) != `[{"name":"acts","max-age-days":400}]` {
+		t.Fatalf("an aged log written back as %s", out)
+	}
+	for _, edge := range []string{`{"name":"a","max-mib":1}`, `{"name":"a","max-mib":8192}`, `{"name":"a","max-age-days":3650}`} {
 		if _, err := ParseManifest([]byte(`{"module":"a","version":"1","logs":[` + edge + `]}`)); err != nil {
 			t.Errorf("%s is inside the caps and was refused: %v", edge, err)
 		}
@@ -42,7 +50,8 @@ func TestALogIsNamedLocallyAndCapped(t *testing.T) {
 		{`{"module":"a","version":"1","logs":[{"name":"c","max-mib":8193}]}`, `between 1 and 8192 MiB`},
 		{`{"module":"a","version":"1","logs":[{"name":"c","max-mib":-1}]}`, `between 1 and 8192 MiB`},
 		{`{"module":"a","version":"1","logs":[{"name":"c","max-mib":0}]}`, `max-mib is between 1 and 8192, not 0`},
-		{`{"module":"a","version":"1","logs":[{"name":"c","stream":"LOG_x"}]}`, `{name, max-mib}`},
+		{`{"module":"a","version":"1","logs":[{"name":"c","stream":"LOG_x"}]}`, `{name, max-mib, max-age-days}`},
+		{`{"module":"a","version":"1","logs":[{"name":"c","max-age-days":0}]}`, `max-age-days is between 1 and 3650, not 0`},
 		{`{"module":"a.b","version":"1","logs":["c"]}`, `no dot`},
 	} {
 		_, err := ParseManifest([]byte(c.manifest))