How can i plot a colour graph with 3 variables, concentration, time 24 hrs, days?

How can I plot a diurnal colour graph with 24hrs on x-axis, dates with Y axis and concentration of pollutants with respect to day and 24 hrs making a colour plot as shown in the image below.

Please suggest its urgent

.

[Joseph Cheng]

is your data already in a grid? or scatter plot for hour vs month

[Parth Sarathi]

I have given my data for 30 days which I want to plot.

Please suggest In y axis it will be date In X axis it will be hour and considering x days y hour would be the concentration of pollutant. This would give a graph as shown in the original question.