Hass api with custom datetime?

Hi,

Hass is just awesome, great tool !
I used OpenHAB, Jeedom, Z-way, Hass is so delicious.

I would like to use hass api to set entity state (cf. REST API | Home Assistant Developer Docs). I have an input file with datetime and values. I want to parse my file and call hass api using datetime and value. However, state api doesn’t seems to allow a custom datetime, it used current datetime.

{
    "state": "below_horizon",
    "attributes": {
        "next_rising":"2016-05-31T03:39:14+00:00",
        "next_setting":"2016-05-31T19:16:42+00:00"
    }
}

Is it possible to set a custom datetime ?

Best regards !

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