<p>It seems to me that the field <code>time_lock_delta</code> in LND corresponds to what <a href="https://github.com/lightningnetwork/lightning-rfc/blob/master/07-routing-gossip.md" rel="nofollow noreferrer">BOLT#7</a> refers to as <code>cltv_expiry_delta</code>. Which the specification explains to be "the number of blocks it will subtract from an incoming HTLC's <code>cltv_expiry</code>".</p>

<p>Hence, the unit would be a count of blocks.</p>

CC BY-SA 4.0
2019-04-25T22:00:20.043Z
2019-04-25T22:00:20.043Z
Murch
<p>The <code>time_lock_delta</code> is the minimum difference in the number of blocks between the CLTV of an incoming HTLC and the forwarded HTLC.</p>

<p>Full details are described in <a href="https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md#cltv_expiry_delta-selection" rel="nofollow noreferrer">BOLT2 # CLTV expiry delta</a>.</p>

CC BY-SA 4.0
2019-04-25T21:58:38.830Z
2019-04-25T21:58:38.830Z
Mark H
<p>LND has a configuration setting called <code>time_lock_delta</code> with the description "The required timelock delta for HTLCs forwarded over the channel.". I assume this to refer to some measure of time, but what is the unit of this value?</p>

<p><a href="https://i.sstatic.net/wYIza.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/wYIza.png" alt="Screnshot of LND documentation"></a></p>

<p>None of the four files in the LND repository that contain this string appear to mention the unit either.</p>

<terminology><lightning-network-daemon><channels>
What is the unit of time_lock_delta in LND?
Murch
# What is the unit of time_lock_delta in LND?

(Asked by: username_0 on 2019-04-25)

LND has a configuration setting called `time_lock_delta` with the description "The required timelock delta for HTLCs forwarded over the channel.". I assume this to refer to some measure of time, but what is the unit of this value?

[![Screnshot of LND documentation](https://i.sstatic.net/wYIza.png)](https://i.sstatic.net/wYIza.png)

None of the four files in the LND repository that contain this string appear to mention the unit either.

**Tags:** terminology, lightning-network-daemon, channels


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## 2 answers

### Answer by username_1 on 2019-04-25. Score: 4 | Accepted answer

The `time_lock_delta` is the minimum difference in the number of blocks between the CLTV of an incoming HTLC and the forwarded HTLC.

Full details are described in [BOLT2 # CLTV expiry delta](https://github.com/lightningnetwork/lightning-rfc/blob/master/02-peer-protocol.md#cltv_expiry_delta-selection).


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### Answer by username_0 on 2019-04-25. Score: 2

It seems to me that the field `time_lock_delta` in LND corresponds to what [BOLT#7](https://github.com/lightningnetwork/lightning-rfc/blob/master/07-routing-gossip.md) refers to as `cltv_expiry_delta`. Which the specification explains to be "the number of blocks it will subtract from an incoming HTLC's `cltv_expiry`".

Hence, the unit would be a count of blocks.


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