Scripting Azure DevOps build schedule produces unexpected results

Question

This question is related to How to script build schedule using Azure DevOps REST Api?

Given:

• A script to set build schedule is run at 7:59am EST
• The schedule is every 5 minutes regardless of the changes every day in EST on master
• According to Fiddler:

   ClientConnected:    07:59:28.854
   ClientBeginRequest: 08:00:44.334
   GotRequestHeaders:  08:00:44.334
   ClientDoneRequest:  08:00:44.334

• The response headers contain Date: Wed, 06 Nov 2019 13:00:49 GMT
• The PUT request contains the following JSON fragment (see the text below):
• The PUT request response:

So, here is the JSON request body fragment related to the schedules:

 "schedules":  [
                   {
                       "branchFilters":  [
                                             "+refs/heads/master"
                                         ],
                       "startMinutes":  59,
                       "scheduleOnlyWithChanges":  false,
                       "startHours":  7,
                       "timeZoneId":  "Eastern Standard Time",
                       "daysToBuild":  127
                   },
                   {
                       "branchFilters":  [
                                             "+refs/heads/master"
                                         ],
                       "startMinutes":  4,
                       "scheduleOnlyWithChanges":  false,
                       "startHours":  8,
                       "timeZoneId":  "Eastern Standard Time",
                       "daysToBuild":  127
                   },
                   {
                       "branchFilters":  [
                                             "+refs/heads/master"
                                         ],
                       "startMinutes":  9,
                       "scheduleOnlyWithChanges":  false,
                       "startHours":  8,
                       "timeZoneId":  "Eastern Standard Time",
                       "daysToBuild":  127
                   },
...

And the respective response JSON fragment is:

"schedules": [
    {
        "branchFilters": [
            "+refs/heads/master"
        ],
        "timeZoneId": "Eastern Standard Time",
        "startHours": 7,
        "startMinutes": 59,
        "daysToBuild": "all",
        "scheduleJobId": "21a1da8a-e508-40ad-8716-d3e1483f05d7",
        "scheduleOnlyWithChanges": false
    },
    {
        "branchFilters": [
            "+refs/heads/master"
        ],
        "timeZoneId": "Eastern Standard Time",
        "startHours": 8,
        "startMinutes": 4,
        "daysToBuild": "all",
        "scheduleJobId": "425eaa93-9f35-4dcb-aeb0-437479caab8d",
        "scheduleOnlyWithChanges": false
    },
    {
        "branchFilters": [
            "+refs/heads/master"
        ],
        "timeZoneId": "Eastern Standard Time",
        "startHours": 8,
        "startMinutes": 9,
        "daysToBuild": "all",
        "scheduleJobId": "a109daa2-f65b-4792-b599-594fdf1363ca",
        "scheduleOnlyWithChanges": false
    },
...

So far so good. Given all that my expectation is to find the schedules starting at 7:59 (because that is what I am asking and the response confirms it) in EST and the first schedule kick in at 8:04 EST.

However, this is not the case. Observe the actual result:

• The schedule as it appears in the GUI: ...
• And the actual scheduled builds as reported by the build history:

The schedules do cover the entire 24 hour range at 5 minute intervals as expected. But:

1. Why does the first scheduled build happen at 9:04am EST instead of 8:04am EST?
2. Why do the schedules in the GUI start at 4:14am?