# zeroTime

```ts
import { zeroTime } from 'cx/util';
```


Sets the time portion of a date to midnight (00:00:00.000).

## Signature

```ts
function zeroTime(date: Date): Date
```

## Examples

```ts
const date = new Date("2026-01-21T14:30:45.123");
const midnight = zeroTime(date);
// 2026-01-21T00:00:00.000

// Original is unchanged
console.log(date.getHours()); // 14
console.log(midnight.getHours()); // 0
```

## Use Cases

### Date comparison

```ts
function isSameDay(d1: Date, d2: Date): boolean {
  return zeroTime(d1).getTime() === zeroTime(d2).getTime();
}
```

### Date range queries

```ts
const startOfDay = zeroTime(new Date());
const endOfDay = new Date(startOfDay);
endOfDay.setDate(endOfDay.getDate() + 1);

const todaysRecords = records.filter(
  (r) => r.date >= startOfDay && r.date < endOfDay
);
```

## See Also

- [sameDate](/docs/utilities/same-date) - Compare dates ignoring time
- [monthStart](/docs/utilities/month-start) - Get first day of month