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typescript.naive_datetime

Correctness Medium

Detects usage of timezone-unaware date operations that cause subtle bugs.

Why It Matters

Naive datetimes:

Time zone bugs — Comparisons across zones fail
DST issues — Missing/duplicate hours
Data corruption — Stored times are ambiguous

Example

// ❌ Before (naive datetime)
function scheduleTask(at: Date): void {
  // Date is in local time - what if server is in different TZ?
  if (at > new Date()) {
    queue.schedule(at.toISOString());
  }
}

// ✅ After (timezone-aware with luxon)
import { DateTime } from 'luxon';

function scheduleTask(at: DateTime): void {
  if (!at.isValid || !at.zone) {
    throw new Error('Valid DateTime with timezone required');
  }
  if (at > DateTime.utc()) {
    queue.schedule(at.toUTC().toISO());
  }
}

What Unfault Detects

new Date() without timezone context
Date parsing without explicit timezone
toISOString without UTC conversion

Auto-Fix

Unfault can suggest luxon or date-fns-tz usage.