user78: In this talk about Lightning Network, roasbeef speaks about BIP39 as having no support for 'birthdays'. What does that mean?
https://www.youtube.com/watch?v=LXY0L8eeG3k minute 22


user7272: It simply means that BIP39 seeds have no way to tell you when they were created - If you need to check one for transactions, you have to start at the genesis block and work your way up to the present day.
This is in contrast to the traditional Bitcoin-qt wallet.dat, which maintains a date for when the address was created. Usually, it will not check for transactions for that address before that date (if the birthday is missing, it will check from genesis)

78: <p>In this talk about Lightning Network, roasbeef speaks about BIP39 as having no support for 'birthdays'. What does that mean?</p>

<p><a href="https://www.youtube.com/watch?v=LXY0L8eeG3k" rel="nofollow noreferrer">https://www.youtube.com/watch?v=LXY0L8eeG3k</a> minute 22</p>

<p><a href="https://i.stack.imgur.com/Ubh8S.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Ubh8S.png" alt="enter image description here"></a></p>
 7272: <p>It simply means that BIP39 seeds have no way to tell you when they were created - If you need to check one for transactions, you have to start at the genesis block and work your way up to the present day.</p>

<p>This is in contrast to the traditional Bitcoin-qt wallet.dat, which maintains a <a href="https://github.com/bitcoin/bitcoin/blob/979150bc2388de24d532b005e15c654858d8b059/src/wallet/wallet.cpp#L3786" rel="nofollow noreferrer">date for when the address was created</a>. Usually, it will not check for transactions for that address before that date (if the birthday is missing, it will check from genesis)</p>
