API: I don't seem to be able to store dates before 1970?

I don't seem to be able to upload files with dates before 1970.  Here is an example transaction I made with rclone.

This is not entirely surprising since 1970-01-01 is the unix epoch and dates before that will be negative.

However dates before 1970 are supported in Google drive (for instance).

I searched the API docs and I couldn't find this limitation documented - apologies in advance if I missed the documentation.

2018/05/08 13:33:53 DEBUG : HTTP REQUEST (req 0xc42033a200)
2018/05/08 13:33:53 DEBUG : POST /api/2.0/files/content HTTP/1.1
Host: upload.box.com
User-Agent: rclone/v1.41-032-g15256f3d-copy-file
Transfer-Encoding: chunked
Authorization: XXXX
Content-Type: multipart/form-data; boundary=a37d853162f89f544a8fc168f24954a9072a82ffd9fd837d77098b4339a1
Accept-Encoding: gzip

207
--a37d853162f89f544a8fc168f24954a9072a82ffd9fd837d77098b4339a1
Content-Disposition: form-data; name="attributes"

{"name":"hello.txt","parent":{"id":"***number removed for privacy***05"},"content_created_at":"1944-01-01T01:01:00+01:00","content_modified_at":"1944-01-01T01:01:00+01:00"}
--a37d853162f89f544a8fc168f24954a9072a82ffd9fd837d77098b4339a1
Content-Disposition: form-data; name="contents"; filename="hello.txt"
Content-Type: application/octet-stream

hello

--a37d853162f89f544a8fc168f24954a9072a82ffd9fd837d77098b4339a1--

0

Response

2018/05/08 13:33:53 DEBUG : HTTP RESPONSE (req 0xc42033a200)
2018/05/08 13:33:53 DEBUG : HTTP/1.1 400 Bad Request
Content-Length: 470
Age: 0
Cache-Control: no-cache, no-store
Connection: keep-alive
Content-Type: application/json
Date: Tue, 08 May 2018 12:33:53 GMT
Strict-Transport-Security: max-age=31536000
Vary: Accept-Encoding

{"type":"error","status":400,"code":"bad_request","context_info":{"errors":[{"reason":"invalid_parameter","name":"content_created_at","message":"Invalid value '-***number removed for privacy***'. Value must be greater than or equal to 0"},{"reason":"invalid_parameter","name":"content_updated_at","message":"Invalid value '-***number removed for privacy***'. Value must be greater than or equal to 0"}]},"help_url":"http:\/\/developers.box.com\/docs\/#errors","message":"Bad Request","request_id":"mmgizkfr47knmudw"}