Redmine

I could not reproduce the problem. Could you describe detailed steps to reproduce?

Create an issue, then log time against that issue with a "spent_on" date from before the create date of the issue. Then pull that time via the API.

For me, the "spent_on" date changes to the create date of the issue, not the spent_on date of the time entry.

I still cannot reproduce it on the current trunk (3.4.6.devel.17428).

I created an issue #148 on 2018-07-03. Then, logged 12 hours of spent time for 2018-07-01. After that, I made an API request and got the following response. The value for "spent_on" is "2018-07-01". I could not find any problem.

{
  "time_entry": {
    "id": 41,
    "project": {
      "id": 1,
      "name": "eCookbook" 
    },
    "issue": {
      "id": 148
    },
    "user": {
      "id": 1,
      "name": "Admin Redmine" 
    },
    "activity": {
      "id": 10,
      "name": "Development" 
    },
    "hours": 12,
    "comments": "",
    "spent_on": "2018-07-01",
    "created_on": "2018-07-03T07:00:18Z",
    "updated_on": "2018-07-03T07:00:18Z",
    "custom_fields": [
      {
        "id": 10,
        "name": "Overtime",
        "value": "0" 
      }
    ]
  }
}