Variation type

Achievement time periods (could be multi-choices)

Periodical daily variation

In the morning (from 6:00 to 10:00)

In the noon (from 10:00 to 14:00)

In the afternoon (from 14:00 to 18:00)

In the evening (from 18:00 to 22:00)

In the midnight (from 22:00 to 2:00)

In the dawn (from 2:00 to 6:00)

Periodical seasonal variation

Summer (from June to August)

Autumn (from September to November)

Winter (from December to February)

Spring (from March to May)

Sequential variations

Every hour

Every day

Every week

Every month

Every year

Sudden variations

Along with big events (earthquakes, floods,…)

Along with medium events (sudden pollutants, peak periods,…)

Along with small events (sudden light, noise, dust,…)