Seafile and R2 storage, "date didn't parse successfully"

I am currently experimenting setting up R2 as the storage backend for the file managing and sharing tool Seafile https://seafile.com/. The configuration is easy, but Seafile is unable to write to any R2 bucket. Relevant part from the Seafile log:

2023-10-16 10:25:51 ../common/s3-client.c(949): S3 error status for HEAD: 400.
2023-10-16 10:25:51 ../common/s3-client.c(725): S3 error status for PUT: 400.
2023-10-16 10:25:51 ../common/s3-client.c(726): Request URL: https://zzz.r2.cloudflarestorage.com/seafile-commit/85c0832a-3f51-4048-b99a-d5687bc48880/2e59c01c240cc087514acb013e5a787bd7607b77
2023-10-16 10:25:51 ../common/s3-client.c(727): Request headers:
2023-10-16 10:25:51 ../common/s3-client.c(624): Date: Mon, 16 Oct 2023 10:25:51 +0000
2023-10-16 10:25:51 ../common/s3-client.c(624): Authorization: AWS4-HMAC-SHA256 Credential=zzz/20231016/auto/s3/aws4_request,SignedHeaders=host;x-amz-content-sha256,Signature=zzz
2023-10-16 10:25:51 ../common/s3-client.c(624): x-amz-content-sha256: f3f9b62407881ed11c004b4083c1df5ed4167bdd2c791a3f0923ca7dd179b891
2023-10-16 10:25:51 ../common/obj-backend-s3.c(348): Put object 2e59c01c240cc087514acb013e5a787bd7607b77 error 400. Response:
<?xml version="1.0" encoding="UTF-8"?><Error><Code>InvalidArgument</Code><Message>**Invalid Argument: Date provided in &apos;date&apos; header (Mon, 16 Oct 2023 10:25:51 +0000) didn&apos;t parse successfully**</Message></Error>
2023-10-16 10:25:51 repo-mgr.c(7176): Failed to add commit.

It appears that R2 rejects the date header content Mon, 16 Oct 2023 10:25:51 +0000. What’s wrong with this date string?

Seafile claims compatibility with at least OpenStack and Ceph object storage apart from AWS.