diff --git a/cache/entity.go b/cache/entity.go
index c82c96e..caf73cb 100644
--- a/cache/entity.go
+++ b/cache/entity.go
@@ -5,6 +5,7 @@
 package cache
 
 import (
+	"errors"
 	"time"
 
 	"github.com/owasp-amass/asset-db/types"
@@ -69,17 +70,14 @@ func (c *Cache) FindEntityById(id string) (*types.Entity, error) {
 func (c *Cache) FindEntityByContent(asset oam.Asset, since time.Time) ([]*types.Entity, error) {
 	c.Lock()
 	entities, err := c.cache.FindEntityByContent(asset, since)
-	if err == nil && len(entities) == 1 {
-		if !since.IsZero() && !since.Before(c.start) {
-			c.Unlock()
-			return entities, err
-		}
-		if _, last, found := c.checkCacheEntityTag(entities[0], "cache_find_entity_by_content"); found && !since.Before(last) {
-			c.Unlock()
-			return entities, err
-		}
+	if err == nil && len(entities) >= 1 {
+		c.Unlock()
+		return entities, nil
 	}
 	c.Unlock()
+	if !since.IsZero() && !since.Before(c.start) {
+		return nil, err
+	}
 
 	var dberr error
 	var dbentities []*types.Entity
@@ -107,14 +105,12 @@ func (c *Cache) FindEntityByContent(asset oam.Asset, since time.Time) ([]*types.
 			Asset:     entity.Asset,
 		}); err == nil {
 			results = append(results, e)
-			if tags, err := c.cache.GetEntityTags(entity, c.start, "cache_find_entity_by_content"); err == nil && len(tags) > 0 {
-				for _, tag := range tags {
-					_ = c.cache.DeleteEntityTag(tag.ID)
-				}
-			}
-			_ = c.createCacheEntityTag(entity, "cache_find_entity_by_content", since)
 		}
 	}
+
+	if len(results) == 0 {
+		return nil, errors.New("zero entities found")
+	}
 	return results, nil
 }
 
diff --git a/cache/entity_test.go b/cache/entity_test.go
index d01eddb..124cab4 100644
--- a/cache/entity_test.go
+++ b/cache/entity_test.go
@@ -10,7 +10,9 @@ import (
 	"testing"
 	"time"
 
+	"github.com/caffix/stringset"
 	"github.com/owasp-amass/asset-db/types"
+	oam "github.com/owasp-amass/open-asset-model"
 	"github.com/owasp-amass/open-asset-model/domain"
 	"github.com/stretchr/testify/assert"
 )
@@ -142,6 +144,238 @@ func TestFindEntityById(t *testing.T) {
 	}
 }
 
+func TestFindEntityByContent(t *testing.T) {
+	db1, db2, dir, err := createTestRepositories()
+	assert.NoError(t, err)
+	defer func() {
+		db1.Close()
+		db2.Close()
+		os.RemoveAll(dir)
+	}()
+
+	c, err := New(db1, db2)
+	assert.NoError(t, err)
+	defer c.Close()
+
+	// add some really old stuff to the database
+	now := time.Now()
+	ctime1 := now.Add(-24 * time.Hour)
+	cbefore1 := ctime1.Add(-20 * time.Second)
+	fqdn1 := &domain.FQDN{Name: "owasp.org"}
+	entity1, err := c.db.CreateEntity(&types.Entity{
+		CreatedAt: ctime1,
+		LastSeen:  ctime1,
+		Asset:     fqdn1,
+	})
+	assert.NoError(t, err)
+	// add some not so old stuff to the database
+	ctime2 := now.Add(-8 * time.Hour)
+	cbefore2 := ctime2.Add(-20 * time.Second)
+	fqdn2 := &domain.FQDN{Name: "utica.edu"}
+	entity2, err := c.db.CreateEntity(&types.Entity{
+		CreatedAt: ctime2,
+		LastSeen:  ctime2,
+		Asset:     fqdn2,
+	})
+	assert.NoError(t, err)
+	// add new entities to the database
+	fqdn3 := &domain.FQDN{Name: "sunypoly.edu"}
+	entity3, err := c.CreateEntity(&types.Entity{
+		CreatedAt: now,
+		LastSeen:  now,
+		Asset:     fqdn3,
+	})
+	assert.NoError(t, err)
+	after := time.Now().Add(2 * time.Second)
+
+	_, err = c.FindEntityByContent(fqdn3, after)
+	assert.Error(t, err)
+
+	entities, err := c.FindEntityByContent(fqdn3, now)
+	assert.NoError(t, err)
+	if len(entities) != 1 {
+		t.Errorf("first request failed to produce the expected number of entities")
+	}
+
+	e := entities[0]
+	if !reflect.DeepEqual(e.Asset, entity3.Asset) {
+		t.Errorf("DeepEqual failed for the assets in the two entities")
+	}
+
+	_, err = c.FindEntityByContent(fqdn2, c.StartTime())
+	assert.Error(t, err)
+
+	entities, err = c.FindEntityByContent(fqdn2, cbefore2)
+	assert.NoError(t, err)
+	if len(entities) != 1 {
+		t.Errorf("second request failed to produce the expected number of entities")
+	}
+
+	e = entities[0]
+	if !reflect.DeepEqual(e.Asset, entity2.Asset) {
+		t.Errorf("DeepEqual failed for the assets in the two entities")
+	}
+
+	_, err = c.FindEntityByContent(fqdn1, cbefore2)
+	assert.Error(t, err)
+
+	entities, err = c.FindEntityByContent(fqdn1, cbefore1)
+	assert.NoError(t, err)
+	if len(entities) != 1 {
+		t.Errorf("third request failed to produce the expected number of entities")
+	}
+
+	e = entities[0]
+	if !reflect.DeepEqual(e.Asset, entity1.Asset) {
+		t.Errorf("DeepEqual failed for the assets in the two entities")
+	}
+}
+
+func TestFindEntitiesByType(t *testing.T) {
+	db1, db2, dir, err := createTestRepositories()
+	assert.NoError(t, err)
+	defer func() {
+		db1.Close()
+		db2.Close()
+		os.RemoveAll(dir)
+	}()
+
+	c, err := New(db1, db2)
+	assert.NoError(t, err)
+	defer c.Close()
+
+	set1 := stringset.New()
+	defer set1.Close()
+	// add some really old stuff to the database
+	now := time.Now()
+	ctime1 := now.Add(-24 * time.Hour)
+	cbefore1 := ctime1.Add(-20 * time.Second)
+	cafter1 := ctime1.Add(20 * time.Second)
+	for _, name := range []string{"owasp.org", "utica.edu", "sunypoly.edu"} {
+		set1.Insert(name)
+		_, err := c.db.CreateEntity(&types.Entity{
+			CreatedAt: ctime1,
+			LastSeen:  ctime1,
+			Asset:     &domain.FQDN{Name: name},
+		})
+		assert.NoError(t, err)
+	}
+
+	set2 := stringset.New()
+	defer set2.Close()
+	// add some not so old stuff to the database
+	ctime2 := now.Add(-8 * time.Hour)
+	cbefore2 := ctime2.Add(-20 * time.Second)
+	cafter2 := ctime2.Add(20 * time.Second)
+	for _, name := range []string{"www.owasp.org", "www.utica.edu", "www.sunypoly.edu"} {
+		set2.Insert(name)
+		_, err := c.db.CreateEntity(&types.Entity{
+			CreatedAt: ctime2,
+			LastSeen:  ctime2,
+			Asset:     &domain.FQDN{Name: name},
+		})
+		assert.NoError(t, err)
+	}
+
+	set3 := stringset.New()
+	defer set3.Close()
+	// add new entities to the database
+	after := now.Add(20 * time.Second)
+	for _, name := range []string{"ns1.owasp.org", "ns1.utica.edu", "ns1.sunypoly.edu"} {
+		set3.Insert(name)
+		_, err := c.CreateAsset(&domain.FQDN{Name: name})
+		assert.NoError(t, err)
+	}
+
+	// no results should be produced with this since param
+	_, err = c.FindEntitiesByType(oam.FQDN, after)
+	assert.Error(t, err)
+
+	entities, err := c.FindEntitiesByType(oam.FQDN, c.StartTime())
+	assert.NoError(t, err)
+	if len(entities) != 3 {
+		t.Errorf("first request failed to produce the expected number of entities")
+	}
+
+	for _, entity := range entities {
+		if fqdn, ok := entity.Asset.(*domain.FQDN); ok {
+			set1.Remove(fqdn.Name)
+			set2.Remove(fqdn.Name)
+			set3.Remove(fqdn.Name)
+		}
+	}
+
+	// only entities from set3 should have been removed
+	if set1.Len() != 3 || set2.Len() != 3 || set3.Len() != 0 {
+		t.Errorf("first request failed to produce the correct entities")
+	}
+	// there shouldn't be a tag for this entity, since it didn't require the database
+	_, err = c.cache.GetEntityTags(entities[0], now, "cache_find_entities_by_type")
+	assert.Error(t, err)
+
+	entities, err = c.FindEntitiesByType(oam.FQDN, ctime2)
+	assert.NoError(t, err)
+	if len(entities) != 6 {
+		t.Errorf("second request failed to produce the expected number of entities")
+	}
+
+	for _, entity := range entities {
+		if fqdn, ok := entity.Asset.(*domain.FQDN); ok {
+			set1.Remove(fqdn.Name)
+			set2.Remove(fqdn.Name)
+			set3.Remove(fqdn.Name)
+		}
+	}
+
+	// only entities from set3 should have been removed
+	if set1.Len() != 3 || set2.Len() != 0 || set3.Len() != 0 {
+		t.Errorf("second request failed to produce the correct entities")
+	}
+	// there should be a tag for this entity
+	tags, err := c.cache.GetEntityTags(entities[0], time.Time{}, "cache_find_entities_by_type")
+	assert.NoError(t, err)
+	if len(tags) != 1 {
+		t.Errorf("second request failed to produce the expected number of entity tags")
+	}
+
+	tagtime, err := time.Parse(time.RFC3339Nano, tags[0].Property.Value())
+	assert.NoError(t, err)
+	if tagtime.Before(cbefore2) || tagtime.After(cafter2) {
+		t.Errorf("tag time: %s, before time: %s, after time: %s", tagtime.Format(time.RFC3339Nano), cbefore2.Format(time.RFC3339Nano), cafter2.Format(time.RFC3339Nano))
+	}
+
+	entities, err = c.FindEntitiesByType(oam.FQDN, ctime1)
+	assert.NoError(t, err)
+	if len(entities) != 9 {
+		t.Errorf("third request failed to produce the expected number of entities")
+	}
+
+	for _, entity := range entities {
+		if fqdn, ok := entity.Asset.(*domain.FQDN); ok {
+			set1.Remove(fqdn.Name)
+			set2.Remove(fqdn.Name)
+			set3.Remove(fqdn.Name)
+		}
+	}
+
+	// only entities from set3 should have been removed
+	if set1.Len() != 0 || set2.Len() != 0 || set3.Len() != 0 {
+		t.Errorf("third request failed to produce the correct entities")
+	}
+	// there should now be a new tag for this entity
+	tags, err = c.cache.GetEntityTags(entities[0], time.Time{}, "cache_find_entities_by_type")
+	assert.NoError(t, err)
+	if len(tags) != 1 {
+		t.Errorf("third request failed to produce the expected number of entity tags")
+	}
+
+	tagtime, err = time.Parse(time.RFC3339Nano, tags[0].Property.Value())
+	assert.NoError(t, err)
+	if tagtime.Before(cbefore1) || tagtime.After(cafter1) {
+		t.Errorf("tag time: %s, before time: %s, after time: %s", tagtime.Format(time.RFC3339Nano), cbefore1.Format(time.RFC3339Nano), cafter1.Format(time.RFC3339Nano))
+	}
+}
+
 func TestDeleteEntity(t *testing.T) {
 	db1, db2, dir, err := createTestRepositories()
 	assert.NoError(t, err)
diff --git a/cache/tag.go b/cache/tag.go
index b22de85..2d99a31 100644
--- a/cache/tag.go
+++ b/cache/tag.go
@@ -418,14 +418,14 @@ func (c *Cache) DeleteEdgeTag(id string) error {
 func (c *Cache) createCacheEntityTag(entity *types.Entity, name string, since time.Time) error {
 	_, err := c.cache.CreateEntityProperty(entity, &property.SimpleProperty{
 		PropertyName:  name,
-		PropertyValue: time.Now().Format("2006-01-02 15:04:05"),
+		PropertyValue: since.Format(time.RFC3339Nano),
 	})
 	return err
 }
 
 func (c *Cache) checkCacheEntityTag(entity *types.Entity, name string) (*types.EntityTag, time.Time, bool) {
 	if tags, err := c.cache.GetEntityTags(entity, time.Time{}, name); err == nil && len(tags) == 1 {
-		if t, err := time.Parse("2006-01-02 15:04:05", tags[0].Property.Value()); err == nil {
+		if t, err := time.Parse(time.RFC3339Nano, tags[0].Property.Value()); err == nil {
 			return tags[0], t, true
 		}
 	}
@@ -435,14 +435,14 @@ func (c *Cache) checkCacheEntityTag(entity *types.Entity, name string) (*types.E
 func (c *Cache) createCacheEdgeTag(edge *types.Edge, name string, since time.Time) error {
 	_, err := c.cache.CreateEdgeProperty(edge, &property.SimpleProperty{
 		PropertyName:  name,
-		PropertyValue: time.Now().Format("2006-01-02 15:04:05"),
+		PropertyValue: since.Format(time.RFC3339Nano),
 	})
 	return err
 }
 
 func (c *Cache) checkCacheEdgeTag(edge *types.Edge, name string) (*types.EdgeTag, time.Time, bool) {
 	if tags, err := c.cache.GetEdgeTags(edge, time.Time{}, name); err == nil && len(tags) == 1 {
-		if t, err := time.Parse("2006-01-02 15:04:05", tags[0].Property.Value()); err == nil {
+		if t, err := time.Parse(time.RFC3339Nano, tags[0].Property.Value()); err == nil {
 			return tags[0], t, true
 		}
 	}
diff --git a/go.mod b/go.mod
index 064590a..5046868 100644
--- a/go.mod
+++ b/go.mod
@@ -4,13 +4,13 @@ go 1.23.1
 
 require (
 	github.com/caffix/queue v0.3.1
+	github.com/caffix/stringset v0.2.0
 	github.com/glebarez/sqlite v1.11.0
 	github.com/owasp-amass/open-asset-model v0.12.0
 	github.com/rubenv/sql-migrate v1.7.0
 	github.com/stretchr/testify v1.9.0
 	gorm.io/datatypes v1.2.4
 	gorm.io/driver/postgres v1.5.9
-	gorm.io/driver/sqlite v1.5.6
 	gorm.io/gorm v1.25.12
 )
 
@@ -41,6 +41,7 @@ require (
 	golang.org/x/text v0.20.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	gorm.io/driver/mysql v1.5.7 // indirect
+	gorm.io/driver/sqlite v1.5.6 // indirect
 	modernc.org/libc v1.61.2 // indirect
 	modernc.org/mathutil v1.6.0 // indirect
 	modernc.org/memory v1.8.0 // indirect
diff --git a/go.sum b/go.sum
index 1cc1172..4a78be1 100644
--- a/go.sum
+++ b/go.sum
@@ -113,8 +113,6 @@ modernc.org/fileutil v1.3.0 h1:gQ5SIzK3H9kdfai/5x41oQiKValumqNTDXMvKo62HvE=
 modernc.org/fileutil v1.3.0/go.mod h1:XatxS8fZi3pS8/hKG2GH/ArUogfxjpEKs3Ku3aK4JyQ=
 modernc.org/gc/v2 v2.5.0 h1:bJ9ChznK1L1mUtAQtxi0wi5AtAs5jQuw4PrPHO5pb6M=
 modernc.org/gc/v2 v2.5.0/go.mod h1:wzN5dK1AzVGoH6XOzc3YZ+ey/jPgYHLuVckd62P0GYU=
-modernc.org/libc v1.61.1 h1:F8JngdWfVzqfNpff2apn7JpBkjq1ss8Ue4KuUdLDM7Q=
-modernc.org/libc v1.61.1/go.mod h1:4QGjNyX3h+rn7V5oHpJY2yH0QN6frt1X+5BkXzwLPCo=
 modernc.org/libc v1.61.2 h1:dkO4DlowfClcJYsvf/RiK6fUwvzCQTmB34bJLt0CAGQ=
 modernc.org/libc v1.61.2/go.mod h1:4QGjNyX3h+rn7V5oHpJY2yH0QN6frt1X+5BkXzwLPCo=
 modernc.org/mathutil v1.6.0 h1:fRe9+AmYlaej+64JsEEhoWuAYBkOtQiMEU7n/XgfYi4=
diff --git a/repository/sqlrepo/tag.go b/repository/sqlrepo/tag.go
index 259f0a0..de086e0 100644
--- a/repository/sqlrepo/tag.go
+++ b/repository/sqlrepo/tag.go
@@ -5,6 +5,7 @@
 package sqlrepo
 
 import (
+	"errors"
 	"strconv"
 	"time"
 
@@ -171,6 +172,9 @@ func (sql *sqlRepository) GetEntityTags(entity *types.Entity, since time.Time, n
 		}
 	}
 
+	if len(results) == 0 {
+		return nil, errors.New("zero tags found")
+	}
 	return results, nil
 }
 
@@ -354,6 +358,9 @@ func (sql *sqlRepository) GetEdgeTags(edge *types.Edge, since time.Time, names .
 		}
 	}
 
+	if len(results) == 0 {
+		return nil, errors.New("zero tags found")
+	}
 	return results, nil
 }