Why Does My WooCommerce Subscription Renew at Odd Hours?

Why This Happens

WordPress stores and calculates scheduled times based on its configured timezone (Settings → General), which may not match the timezone the store owner personally works in, or the customer's own local timezone. Separately, Action Scheduler only processes a due action the next time cron actually runs — if cron only fires every 15 minutes, or worse, only when a visitor happens to load a page (WordPress's default pseudo-cron), a renewal "due" at midnight might not actually process until hours later.

Common Causes

WordPress's timezone setting doesn't match the assumed timezone when reading a renewal date — confirm Settings → General → Timezone reflects what's actually intended.
Low-traffic sites relying on WordPress's default pseudo-cron, which only fires on a page load — a renewal technically due at 2am might not process until the first visitor arrives hours later.
A real server cron job configured to run infrequently (once every few hours, for instance) rather than at a tighter interval, delaying exactly when a due action actually gets picked up.
Confusing the customer's local time with the server's time when reviewing when a renewal "should" have happened — the server's configured timezone is what actually governs the calculation, not wherever the customer happens to be.

How to Fix It

Confirm WordPress's timezone setting is correct for your business, under Settings → General.
Set up a real server cron job on a tight interval (every 5-15 minutes) rather than relying on WordPress's default pseudo-cron, so due actions process close to their actual scheduled time rather than whenever a visitor happens to trigger it.
If exact renewal timing matters for business reasons (billing that should align with a specific reporting cutoff, for instance), account explicitly for the gap between "scheduled time" and "actual processing time" in whatever reporting or reconciliation process depends on it.

See WordPress speed optimization or WooCommerce fixes if scheduling reliability needs a proper server-level fix.