Re: Retry-After in UNIX Timestamp instead of HTTP-Date

Roberto Polli <> Wed, 07 August 2019 14:19 UTC

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From: Roberto Polli <>
Date: Wed, 7 Aug 2019 16:16:14 +0200
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To: =?UTF-8?Q?Philipp_Junghann=C3=9F?= <>
Cc: Wenbo Zhu <>, Amos Jeffries <>, HTTP Working Group <>
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Subject: Re: Retry-After in UNIX Timestamp instead of HTTP-Date
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Thanks @all for your replies!

Il giorno mar 6 ago 2019 alle ore 21:03 Philipp Junghannß
<> ha scritto:
>>> delay in whatever time unit needed is a good Idea,
>>> [..] without needing to care for DST, leap days/seconds or whatever,

> ... the advantage over the unixtime is that you dont get to deal with the Year 2038 problem

Am Mo., 5. Aug. 2019 um 14:06 Uhr schrieb Amos Jeffries <>nz>:
>> Wenbo Zhu <>om>:
>> And it needs to be a float type (32-bit) to support sub-second intervals. (also my earlier question on "Prefer: timeout= ...."  ... )
>Is it really worth telling a client to re-try in less than a second?
> At those timescales the server can just queue the request and answer
> when it can.
I agree with Amos about subsecond precision, as we have network and processing
latency and clock skew.

@wenboz, can you provide some use case where subsecond precision
can be effectively used?

As I wrote in
I'm writing an I-D on RateLimit headers and I'm investigating
the relations between those headers and Retry-After.

Thanks for your feedback
and have a nice day,