Analyse night light dynamics
Step 1: import the nightlight image collection and display the results
// import the nightlight image collection
var nightlight = ee.ImageCollection("NOAA/VIIRS/DNB/MONTHLY_V1/VCMSLCFG").select("avg_rad");
Map.addLayer(nightlight.mean(),{min:0,max:10,palette:['000000','700000','808080','FFFF00','ffffff','ffffff','ffffff']},"nightlights");
Step 2: draw an area of interest using the tool on the map.

step 3: rename the geometry to aoi

step 4: Define the chart and print it to the console.
// Define the chart and print it to the console.
var chart =
ui.Chart.image
.series({
imageCollection: nightlight,
region: aoi,
reducer: ee.Reducer.mean(),
scale: 500,
xProperty: 'system:time_start'
})
.setSeriesNames(['avg_rad'])
.setOptions({
title: 'Date',
hAxis: {title: 'Date', titleTextStyle: {italic: false, bold: true}},
vAxis: {
title: 'average nighlight',
titleTextStyle: {italic: false, bold: true}
},
lineWidth: 5,
colors: ['e37d05'],
curveType: 'function'
});
print(chart);
Click this link for the full code.