Bug: Timestamp is 19 seconds off

[gitmachtl]

Testnet Example:
The output for block 3226895 is reported with the timestamp 1641849006.
If i convert this back into an actual date like date --date="@1641849006" i get the date Mon, 10 Jan 2022 22:10:06.
DB-Sync/Explorers report Mon, 10 Jan 2022 22:10:25

So there is a 19 seconds offset. And its for all the reported blocks. So either i am converting it wrong, or there is a Bug?

[mark-stopka]

Probably mistake in well known info...

oura/src/framework.rs

Line 33 in d9dc542

shelley_known_time: 1595967596,

[gitmachtl]

Its also off 19 seconds on mainnet.

[scarmuega]

Event timestamps are inferred from the slot number of the block, but there seems to be some ambiguity on how to translate the interval length between blocks (~20 secs ATM). I found this comment by @KtorZ very insightful:

CardanoSolutions/ogmios#3 (comment)

TBH, I'm not happy with the current approach in Oura. I'll do some reverse engineering on db-sync to understand the logic it uses.