using IF statement on JSON data goes wrong (Android Kotlin)

I'm trying to display the weather forecast for 5 days but the openweathermap gives me the weather for 5 days/3 hours. What i want to do is to display only the weather in 15:00.I'm using an if statement with one of the date&time and if you see my emulator it displays the same date and time many times and also displays the whole JSON file as empty texts.Any idea on this please?

Here is my if statement

if(weatherFor.dt_txt=="2018-08-21 00:00:00") {
            holder?.view?.textWeatherDataForecast?.text = "${weatherFor.weather.map { it.description }.joinToString(",")} on ${date}"
            holder?.view?.tempTextForecast?.text = weatherFor.main.temp.toString() + "°C"

        }