<p><code>epoch</code> and <code>slots</code> are effectively just ways to express time from start of the chain. What you're looking at on adapools is likely the difference between first and last block within an epoch. You can check the epoch start/end time of given epoch, as well as first/last block of epoch at <a href="https://api.koios.rest/#get-/epoch_info" rel="nofollow noreferrer">koios</a></p>

CC BY-SA 4.0
2022-03-07T20:51:02.863Z
2022-03-07T20:51:02.863Z
RdLrT
<p>No, epochs do not overlap. They are also 100% deterministic and exactly 120 hours long (on mainnet).</p>
<p>I cannot answer questions about poolpeek.</p>

CC BY-SA 4.0
2022-03-07T03:11:35.613Z
2022-03-07T03:23:44.303Z
2022-03-07T03:23:44.303Z
Erik de Castro Lopo
<p>The overlap shown is because of the display format of full days. The epoch transitions at 21:44:51 every 5 days, so for most of the day it will be previous epoch and last few hours it will be the new epoch.</p>

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2022-03-09T03:46:21.490Z
2022-03-09T03:46:21.490Z
Samuel Leathers
<p>Is there an actual overlap in epochs (see <a href="https://poolpeek.com/#/epochcalendar" rel="nofollow noreferrer">https://poolpeek.com/#/epochcalendar</a>)? If so why? Or is this only an allowance for timezones, or are epochs somewhat unpredictable.  On a related note on <a href="https://adapools.org/epochs" rel="nofollow noreferrer">https://adapools.org/epochs</a> most epochs are 120 hours, but some are 119.9 hours. Why?
Sorry, Probably a noob question but <a href="https://cardano.stackexchange.com/questions/290/why-do-daedalus-rewards-report-epoch-end-dates-differ-from-other-sources">Why do Daedalus Rewards Report Epoch End Dates differ from other sources?</a> doesn't quite seem relevant to my question.</p>

<epoch>
Overlap in epochs
# Overlap in epochs

(Asked by: username_0 on 2022-03-07)

Is there an actual overlap in epochs (see <https://poolpeek.com/#/epochcalendar>)? If so why? Or is this only an allowance for timezones, or are epochs somewhat unpredictable. On a related note on <https://adapools.org/epochs> most epochs are 120 hours, but some are 119.9 hours. Why?
Sorry, Probably a noob question but [Why do Daedalus Rewards Report Epoch End Dates differ from other sources?](https://cardano.stackexchange.com/questions/290/why-do-daedalus-rewards-report-epoch-end-dates-differ-from-other-sources) doesn't quite seem relevant to my question.

**Tags:** epoch

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## 3 answers

### Answer by username_1 on 2022-03-07. Score: 1 | Accepted answer

`epoch` and `slots` are effectively just ways to express time from start of the chain. What you're looking at on adapools is likely the difference between first and last block within an epoch. You can check the epoch start/end time of given epoch, as well as first/last block of epoch at [koios](https://api.koios.rest/#get-/epoch_info)


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### Answer by username_2 on 2022-03-07. Score: 1

No, epochs do not overlap. They are also 100% deterministic and exactly 120 hours long (on mainnet).

I cannot answer questions about poolpeek.


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### Answer by username_3 on 2022-03-09. Score: 1

The overlap shown is because of the display format of full days. The epoch transitions at 21:44:51 every 5 days, so for most of the day it will be previous epoch and last few hours it will be the new epoch.


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