When dealing with time, as well as dates, our data packets will typically use an epoch integer. Our date/times will normally be in UTC/GMT - unless it will be a renderable time to the end user, when it currently will use the 'Europe/London' timezone to take into account daylight savings time.
{
"lastChange": 1691481892,
"time": 1691398800,
"endTime": 1691402400
}