Is blockchain.com reliable for the broadcast date of transactions?

[Saint-loup]

Is blockchain.com really reliable for the broadcast date of transactions?

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[o_e_l_e_o]

Is blockchain.com really reliable for the broadcast date of a transaction?

The "Received time" for each transaction on blockchain.com will be the time it was first broadcast to the node or nodes that blockchain.com use to source their data for their block explorer. If the mempool isn't so full that low fee transactions are being dropped by the majority of nodes, then it will almost certainly be accurate for the date. It may be several minutes out for the exact time, depending on how long it took a transaction to spread through the network (which could theoretically affect the date for transactions made within a few minutes of midnight).

[Saint-loup]

Is blockchain.com really reliable for the broadcast date of a transaction?

The "Received time" for each transaction on blockchain.com will be the time it was first broadcast to the node or nodes that blockchain.com use to source their data for their block explorer. If the mempool isn't so full that low fee transactions are being dropped by the majority of nodes, then it will almost certainly be accurate for the date. It may be several minutes out for the exact time, depending on how long it took a transaction to spread through the network (which could theoretically affect the date for transactions made within a minute or two of midnight).

The date shown on blockchain.com of my last transaction is 3 days late.

[o_e_l_e_o]

For the period of the 19th-25th May, the mempool was generally sitting just shy of the 100 MB mark, which means some nodes may have been dropping or not relaying low fee transactions, which might explain the discrepancy. Otherwise, it means that blockchain.com didn't see your transaction for some other reason. How long ago did you make the transaction? What date is shown on other block explorers? What wallet did you use to broadcast the transaction?

[Pmalek]

I have heard some stories like that before. Blockchain.com explorer showing different data compared to other explorers. I did some searching and found a reddit post from 3 years ago where the OP is claiming that blockchain.com was showing that a transaction went to a completely different address than where it was actually sent. Other block explorers were showing the correct info but not blockchain.com.
https://www.reddit.com/r/Bitcoin/comments/64f2na/blockchaininfo_showing_outright_wrong_information/

Just don't use them if you don't have to for some reason. Blockchair and Blockstream are better anyways.

[Saint-loup]

For the period of the 19th-25th May, the mempool was generally sitting just shy of the 100 MB mark, which means some nodes may have been dropping or not relaying low fee transactions, which might explain the discrepancy. Otherwise, it means that blockchain.com didn't see your transaction for some other reason. How long ago did you make the transaction? What date is shown on other block explorers? What wallet did you use to broadcast the transaction?

AFAIK the size of the mempool impacts the mining date, not the broadcast one.
Which other block explorers are showing broadcast dates please? I only know one other.

I have heard some stories like that before. Blockchain.com explorer showing different data compared to other explorers. I did some searching and found a reddit post from 3 years ago where the OP is claiming that blockchain.com was showing that a transaction went to a completely different address than where it was actually sent. Other block explorers were showing the correct info but not blockchain.com.
https://www.reddit.com/r/Bitcoin/comments/64f2na/blockchaininfo_showing_outright_wrong_information/

Just don't use them if you don't have to for some reason. Blockchair and Blockstream are better anyways.

I don't find this data on those ones (only the mining date)

[o_e_l_e_o]

AFAIK the size of the mempool impacts the mining date, not the broadcast one.

Each node has a maximum size in megabytes which it will use to store unconfirmed transactions. If it hits that limit, then any transaction with a fee lower than the lowest fee transaction it is currently storing will not be added to its mempool and will not be broadcast to other nodes.

Which other block explorers are showing broadcast dates please? I only know one other.

https://live.blockcypher.com - mouse over the "Received" box to get an exact time
https://explorer.bitcoin.com - under "First Seen"

I don't find this data on those ones (only the mining date)

Yeah, the time given on blockchair.com is the time the transaction was received only for unconfirmed transactions. Once the transaction is confirmed, the time updates to the timestamp of the block it was confirmed in.

[Saint-loup]

AFAIK the size of the mempool impacts the mining date, not the broadcast one.

Each node has a maximum size in megabytes which it will use to store unconfirmed transactions. If it hits that limit, then any transaction with a fee lower than the lowest fee transaction it is currently storing will not be added to its mempool and will not be broadcast to other nodes.

Which other block explorers are showing broadcast dates please? I only know one other.

https://live.blockcypher.com - mouse over the "Received" box to get an exact time
https://explorer.bitcoin.com - under "First Seen"

I don't find this data on those ones (only the mining date)

Yeah, the time given on blockchair.com is the time the transaction was received only for unconfirmed transactions. Once the transaction is confirmed, the time updates to the timestamp of the block it was confirmed in.

https://live.blockcypher.com - mouse over the "Received" box to get an exact time -> I get the mining date there
https://explorer.bitcoin.com - under "First Seen" -> the date is OK ie 3 days before the blockchain.com one
The date of my tx is also ok on bitaps.com