Why Your ICP Rewards Were Lower in January

When the first performance-based mint landed on January 13, some node providers noticed something odd.

Their rewards were lower than expected.

Naturally, the first reaction was concern:

Did my nodes get penalized?
Did something go wrong?

But when you checked Node Monitor, everything looked fine. Every node assigned to a subnet showed 100% reward attainment. No penalties. No degraded performance.

So what changed?

It came from how performance-based rewards are calculated.

The Short Version

Your rewards looked smaller because this mint covered 30 days, not the usual 30.4375 days. That’s it. But the reason why matters.

Why Performance-Based Rewards Changed the Calendar

Before performance-based rewards, reward calculation was simple.

There were, no node-level performance metrics, no historical snapshots, no dependency on time granularity.

The system could take the remuneration table, multiply by your number of nodes and apply a fixed period of 30.4375 days (which is 365.25 ÷ 12, where the .25 accounts for leap years).

From that, you had your rewards. Performance-based rewards changed this fundamentally.

Performance-based rewards rely on trustworthy node metrics, and those metrics are stored using daily snapshots. The system stores one canonical snapshot per day, taken after the day completes.

That snapshot becomes the authoritative record for:

node performance
reward calculations
historical queries

Because a snapshot can only exist after a full day has passed, rewards can only be calculated over a whole number of completed days. So while the metrics are live, the set used for reward data is only taken at the end of the day.

Reducing this to sub-day resolution would require a protocol-level change, which would need broader community discussion.

If we take the January mint as an example, the mint prior to January 13 occurred on December 14.

That means for the January mint the reward period covered December 14 → January 12 (inclusive). That’s exactly 30 full days (January 13 was not included as a whole day was not completed)

So there you have it. No missing rewards. No penalties. Just a rewards algorithm that now depends on completed daily snapshots.

“But Doesn’t That Reduce Rewards Over Time?”

It’s a reasonable concern. If rewards are now calculated in 30-day chunks instead of 30.4375 days, doesn’t that missing fraction add up? No because the algorithm has accounted for this explicitly.

Instead of fractional days, the system compensates by adding an extra day every third mint.

Here’s how it plays out:

Mint 1
- Old system: 30.4375 days
- New system: 30 days
Mint 2
- Old system: 60.875 days
- New system: 60 days
Mint 3
- Old system: 91.3125 days
- New system: 91 days

You can see that extra day in the third mint absorbs the accumulated remainder. Over time, roughly 16 months, the total rewards under the old and new systems converge exactly.