# Determine one year from a date

Add one to the UTC year.

Canonical: https://1loc.dev/date-time/determine-one-year-from-now/
Version: 1.0.0
Runtime: JavaScript · Node.js 22 / modern browsers
Verification: Local fixtures; no external services
Updated: 2026-10-28

## Implementation

```javascript
function plusOneYear(date) { const d = new Date(date); d.setUTCFullYear(d.getUTCFullYear() + 1); return d.toISOString().slice(0, 10); }
```

## Input

```json
"2026-10-28"
```

## Expected output

```json
"2027-10-28"
```

## Edge case

Input:
```json
"2024-02-29"
```
Output:
```json
"2025-03-01"
```

## Limits

- February 29 rolls over to March 1 in a non-leap year, as the edge case shows; clamp to February 28 if your contract requires it.

The lab validates types and size before calling this function. Add equivalent validation at your own trust boundary.

## Source and license

Original: https://github.com/phuocng/1loc/blob/14b481cf60dff1620ab1bb99a43b1f68068cdd9b/contents/determine-one-year-from-now.mdx
Source file (this edition): https://github.com/akamind/1loc/blob/0a77f131b22d2ba3b7ec1728846f900c22821678/contents/determine-one-year-from-now.mdx
Author: Nguyen Huu Phuoc and original contributors
Contributors: See original repository history
Source commit: 14b481cf60dff1620ab1bb99a43b1f68068cdd9b
Copyright (c) 2020 phuoc-ng
License: MIT — https://1loc.dev/licenses/
Maintainer: Oveyon
Modifications: Takes the date as an input and documents the February 29 rollover. Original MDX retained as inert source evidence.