[API reference](https://evolu.dev/docs/api-reference) › [@evolu/common](https://evolu.dev/docs/api-reference/common) › [Time](https://evolu.dev/docs/api-reference/common/Time) › TestTime
Defined in: [packages/common/src/Time.ts:191](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L191)
Test [Time](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time) with controllable timers.
Call `advance(ms)` to move time forward and trigger any pending timeouts.
## Extends
- [`Time`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time)
## Properties
### advance
```ts
readonly advance: (duration: Duration) => void;
```
Defined in: [packages/common/src/Time.ts:198](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L198)
Advances time by the specified duration, triggering pending timeouts.
Timeout callback errors propagate and leave time at the callback's
deadline. Throws if called while another advance is in progress.
### clearTimeout
```ts
readonly clearTimeout: (id: TimeoutId) => void;
```
Defined in: [packages/common/src/Time.ts:63](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L63)
Cancels a timeout scheduled with this instance's [Time.setTimeout](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time#settimeout).
Throws if the timeout was scheduled by another [Time](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time) instance.
#### Inherited from
[`Time`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time).[`clearTimeout`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time#cleartimeout)
---
### now
```ts
readonly now: {
(): number & Brand<"NonNaN"> & Brand<"Finite"> & Brand<"Int"> & Brand<"NonNegative"> & Brand<"LessThan281474976710655"> & Brand<"Millis">;
(type: "DateIso"): string & Brand<"DateIso">;
};
```
Defined in: [packages/common/src/Time.ts:30](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L30)
#### Call Signature
```ts
(): number & Brand<"NonNaN"> & Brand<"Finite"> & Brand<"Int"> & Brand<"NonNegative"> & Brand<"LessThan281474976710655"> & Brand<"Millis">;
```
Returns current time as Unix epoch milliseconds.
##### Returns
`number` & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"NonNaN"`\> & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"Finite"`\> & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"Int"`\> & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"NonNegative"`\> & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"LessThan281474976710655"`\> & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"Millis"`\>
#### Call Signature
```ts
(type: "DateIso"): string & Brand<"DateIso">;
```
Returns current time as an ISO 8601 UTC string.
##### Parameters
| Parameter | Type |
| --------- | ----------- |
| `type` | `"DateIso"` |
##### Returns
`string` & [`Brand`](https://evolu.dev/docs/api-reference/common/Brand/interfaces/Brand)\<`"DateIso"`\>
#### Inherited from
[`Time`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time).[`now`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time#now)
---
### performance
```ts
readonly performance: {
now: () => PerformanceTime;
timeOrigin: PerformanceTimeOrigin;
};
```
Defined in: [packages/common/src/Time.ts:38](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L38)
| Name | Type | Description | Defined in |
| ------------ | ------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------ |
| `now()` | () => [`PerformanceTime`](https://evolu.dev/docs/api-reference/common/Time/type-aliases/PerformanceTime) | Returns a high-resolution timestamp in milliseconds relative to `performance.timeOrigin`. Unlike [Time.now](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time#now), this value is not Unix epoch time and is unaffected by system clock adjustments. Like Node.js `process.hrtime.bigint()`, it is suitable for measuring elapsed time, but it uses the Web Performance API's number representation rather than nanoseconds as a bigint. | [packages/common/src/Time.ts:52](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L52) |
| `timeOrigin` | [`PerformanceTimeOrigin`](https://evolu.dev/docs/api-reference/common/Time/type-aliases/PerformanceTimeOrigin) | Unix epoch timestamp used as the origin for `performance.now()`. | [packages/common/src/Time.ts:40](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L40) |
#### Inherited from
[`Time`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time).[`performance`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time#performance)
---
### setTimeout
```ts
readonly setTimeout: (fn: () => void, delay: PositiveDuration) => TimeoutId;
```
Defined in: [packages/common/src/Time.ts:56](https://github.com/evoluhq/evolu/blob/a18269a1b822c670b507c6a9b73b23eed32551fe/packages/common/src/Time.ts#L56)
Schedules a callback after the specified positive delay.
#### Inherited from
[`Time`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time).[`setTimeout`](https://evolu.dev/docs/api-reference/common/Time/interfaces/Time#settimeout)