diff --git a/readme.md b/readme.md
index 3523406..f1f4f9c 100644
--- a/readme.md
+++ b/readme.md
@@ -25,5 +25,4 @@ import {
 	Logger,
 	LogFn,
 } from '@js/types';
-
 ```
diff --git a/src/functions.d.ts b/src/functions.d.ts
new file mode 100644
index 0000000..7f0afd3
--- /dev/null
+++ b/src/functions.d.ts
@@ -0,0 +1,10 @@
+
+export type Func<T extends any = any> = (...args: any[]) => T;
+
+export type Params<T extends Func> = T extends (...args: infer P) => any ? P : never;
+
+export type FirstParam<T extends Func> = T extends (first: infer F, ...args: any[]) => any ? F : never;
+
+export type NonFirstParams<T extends Func> = T extends (first: any, ...args: infer P) => any ? P : never;
+
+export type WithoutFirstParam<T extends Func> = T extends (first: any, ...args: infer P) => infer R ? (...args: P) => R : never;
diff --git a/src/identifiers.d.ts b/src/identifiers.d.ts
index 7e0d388..dee212a 100644
--- a/src/identifiers.d.ts
+++ b/src/identifiers.d.ts
@@ -1,6 +1,12 @@
 
+/** An HTTP URL, e.g. `https://example.com/foo?bar=baz` */
 export type HttpURL = `http://${string}` | `https://${string}`;
 
+/** An HTTP URL without the scheme specified, e.g. `//example.com/foo?bar=baz` */
+export type HttpURLSchemeless = `//${string}`;
+
+/** An RFC 4122 Universally Unique Identifier string */
 export type UUID = `${string}-${string}-${string}-${string}-${string}`;
 
+/** A Snowflake unique identifier string */
 export type SnowflakeID = `${bigint}`;
diff --git a/src/index.d.ts b/src/index.d.ts
index aa0cc5a..98a7efd 100644
--- a/src/index.d.ts
+++ b/src/index.d.ts
@@ -1,4 +1,7 @@
 
+export * from './functions';
 export * from './http';
 export * from './identifiers';
+export * from './locale';
 export * from './logger';
+export * from './time';
diff --git a/src/locale.d.ts b/src/locale.d.ts
new file mode 100644
index 0000000..194a740
--- /dev/null
+++ b/src/locale.d.ts
@@ -0,0 +1,3 @@
+
+/** A combined ISO 639-1 language code and ISO 3166-1 alpha-2 country code, like `en-US` */
+export type Locale = `${string}-${string}`;
diff --git a/src/time.d.ts b/src/time.d.ts
new file mode 100644
index 0000000..9091524
--- /dev/null
+++ b/src/time.d.ts
@@ -0,0 +1,21 @@
+
+/** A date string, formatted `YYYY-MM-DD` */
+export type ISODate = `${number}-${number}-${number}`;
+
+/** A time string, formatted `HH:mm:ss.sss` */
+export type ISOTime = `${number}:${number}:${number}.${number}`;
+
+/**  */
+export type ISOZoneOffset = 'Z' | `${'+' | '-' | ''}${number}:${number}`;
+
+/**  */
+export type ISOTimestamp = `${ISODate}T${ISOTime}${ISOZoneOffset}`;
+
+/** A time string, formatted `HH:mm` */
+export type TimeShort = `${number}:${number}`;
+
+/** A date/time string, formatted `YYYY-MM-DD HH:mm` */
+export type LocalDateTime = `${ISODate} ${TimeShort}`;
+
+/** A timezone identifier string, like `America/Los_Angeles` */
+export type Timezone = `${string}/${string}`;