It clearly shows a giant sine wave and we're very happy on xmas. So... now we should juxtapose the stock market and see how things correlate. Only then will we be able to answer the age old question if money = happiness.
Edit: Also we're much much much happier with our mother than our father. This has soo much info packed into it.
I think the bigger mistake is to think even if it was a good sample it could gauge people’s mood - incentives for posting to social media are either happy or outrage. You will never get a silent majority “just okay” or “neutral-low” by averaging between ecstatic and outraged.
I think the fact that two of the top ~10 happiest days in 2018 were attributed to a Korean pop star's birthday is excellent evidence that people of twitter are not, in fact, good samples of the people of the US.
Looks like a typical seasonality curve. Things tend to repeat at the same period of the year (say, happy in summer, sad in winter). You can see similar patterns at different time scales (weekend vs week, day vs night etc)
Edit: Also we're much much much happier with our mother than our father. This has soo much info packed into it.