How to define a regex-matched string type in Typescript?

There is no way to define such a type. There is a proposal on GitHub to support this, but it currently does not appear to be a priority. Vote on it and maybe the team might include it in a future release.

Edit

Starting in 4.1 you can define a type that would validate the string without actually defining all the options:

type MarkerTime =`${number| ''}${number}:${number}${number}`

let a: MarkerTime = "0-00" // error
let b: MarkerTime = "0:00" // ok
let c: MarkerTime = "09:00" // ok

Playground Link

Until regex types become available to the language, you can now use template literal types in TS 4.1.

Let me refer to the question example and illustrate, how to model a time restricted string type called Time. Time expects strings in the format hh:mm (e.g. "23:59") here for simplification.

Step 1: define HH and MM types

Array.from({length:24},(v,i)=> i).reduce((acc,cur)=> `${acc}${cur === 0 ? "" : "|"}'${String(cur).padStart(2, 0)}'`, "type HH = ")
Array.from({length:60},(v,i)=> i).reduce((acc,cur)=> `${acc}${cur === 0 ? "" : "|"}'${String(cur).padStart(2, 0)}'`, "type MM = ")

type HH = '00'|'01'|'02'|'03'|'04'|'05'|'06'|'07'|...|'22'|'23'
type MM = '00'|'01'|'02'|'03'|'04'|'05'|'06'|'07'|...|'58'|'59'

Step 2: Declare Time

type Time = `${HH}:${MM}`

Simple as that.

Step 3: Some testing

const validTimes: Time[] = ["00:00","01:30", "23:59", "16:30"]
const invalidTimes: Time[] = ["30:00", "23:60", "0:61"] // all emit error

Here is a live code example to get play around with Time.

Basing on the answer of @bela53 but much more simpler, we can do a very simple solution which is similar to what @Titian but without the drawbacks:

type HourPrefix = '0'|'1'|'2';
type MinutePrefix = HourPrefix | '3'|'4'|'5';
type Digit = MinutePrefix |'6'|'7'|'8'|'9';

type Time = `${HourPrefix | ''}${Digit}:${MinutePrefix}${Digit}`

const validTimes: Time[] = ["00:00","01:30", "23:59", "16:30"]
const invalidTimes: Time[] = ["30:00", "23:60", "0:61"] // all emit error

type D1 = 0|1;
type D3 = D1|2|3;
type D5 = D3|4|5;
type D9 = D5|6|7|8|9;

type Hours = `${D9}` | `${D1}${D9}` | `${2}${D3}`;
type Minutes = `${D5}${D9}`;
type Time = `${Hours}:${Minutes}`;

Compact solution aggregating ideas from @bela53 and @yoel halb.

This solution has 2039 enum members for the Time type.

Ts Playground