5 files changed, 20 insertions, 0 deletions
diff --git a/packages/backend/src/misc/id/aid.ts b/packages/backend/src/misc/id/aid.ts
index e7b59f262b..de03f6793f 100644
--- a/packages/backend/src/misc/id/aid.ts
+++ b/packages/backend/src/misc/id/aid.ts
@@ -34,3 +34,7 @@ export function parseAid(id: string): { date: Date; } {
 	const time = parseInt(id.slice(0, 8), 36) + TIME2000;
 	return { date: new Date(time) };
 }
+
+export function isSafeAidT(t: number): boolean {
+	return t > TIME2000;
+}
diff --git a/packages/backend/src/misc/id/aidx.ts b/packages/backend/src/misc/id/aidx.ts
index bed223225a..9f457f6f0a 100644
--- a/packages/backend/src/misc/id/aidx.ts
+++ b/packages/backend/src/misc/id/aidx.ts
@@ -41,3 +41,7 @@ export function parseAidx(id: string): { date: Date; } {
 	const time = parseInt(id.slice(0, TIME_LENGTH), 36) + TIME2000;
 	return { date: new Date(time) };
 }
+
+export function isSafeAidxT(t: number): boolean {
+	return t > TIME2000;
+}
diff --git a/packages/backend/src/misc/id/meid.ts b/packages/backend/src/misc/id/meid.ts
index 366738de05..7646282edb 100644
--- a/packages/backend/src/misc/id/meid.ts
+++ b/packages/backend/src/misc/id/meid.ts
@@ -38,3 +38,7 @@ export function parseMeid(id: string): { date: Date; } {
 		date: new Date(parseInt(id.slice(0, 12), 16) - 0x800000000000),
 	};
 }
+
+export function isSafeMeidT(t: number): boolean {
+	return t > 0;
+}
diff --git a/packages/backend/src/misc/id/meidg.ts b/packages/backend/src/misc/id/meidg.ts
index 426a46970b..f2a55443ef 100644
--- a/packages/backend/src/misc/id/meidg.ts
+++ b/packages/backend/src/misc/id/meidg.ts
@@ -38,3 +38,7 @@ export function parseMeidg(id: string): { date: Date; } {
 		date: new Date(parseInt(id.slice(1, 12), 16)),
 	};
 }
+
+export function isSafeMeidgT(t: number): boolean {
+	return t > 0;
+}
diff --git a/packages/backend/src/misc/id/object-id.ts b/packages/backend/src/misc/id/object-id.ts
index 49bd9591c0..f5c3619fdb 100644
--- a/packages/backend/src/misc/id/object-id.ts
+++ b/packages/backend/src/misc/id/object-id.ts
@@ -38,3 +38,7 @@ export function parseObjectId(id: string): { date: Date; } {
 		date: new Date(parseInt(id.slice(0, 8), 16) * 1000),
 	};
 }
+
+export function isSafeObjectIdT(t: number): boolean {
+	return t > 0;
+}