Overall looks great. Gardening project, moon phases, the notebook has got personality and I like it a lot :)

Some comments as I was going through the notebook:

1. s/lets/let's
2. Suggested edit - redundancy: "In our example, the "processing" is done by PrintElementInfo which simply prints the element with its window information. For windows of three months every month, each element is processed three times, one time per window."
3. Suggested edit - use a bulleted list: "Sliding windows allow us to do just that. We need to specify the window size in seconds just like with FixedWindows. We also need to specify a window period in seconds, which is how often we want to emit each window."
4. Suggested edit - redundancy - future tense: "If the next event happens within the next 30 days or less, like 20 days after the previous event, the session window [will extend and cover..] extends and covers that as well. If there are no new events for the next 30 days, the session window [will close..] closes and is emitted."
5. I had to scroll up to remember what input events look like in the later examples. It would be nice to include a screenshot of the input events to the right of the nice bar charts, then these screenshots can be easily included by other tutorials/talks.

What is the next step on this PR? Could you address the open comments?

Overall looks great. Gardening project, moon phases, the notebook has got personality and I like it a lot :)

Some comments as I was going through the notebook:

1. s/lets/let's

Thanks, done.

2. Suggested edit - redundancy: "In our example, the "processing" is done by PrintElementInfo which simply prints the element with its window information. For windows of three months every month, each element is processed three times, one time per window."

Changed

3. Suggested edit - use a bulleted list: "Sliding windows allow us to do just that. We need to specify the window size in seconds just like with FixedWindows. We also need to specify a window period in seconds, which is how often we want to emit each window."

Changed

4. Suggested edit - redundancy - future tense: "If the next event happens within the next 30 days or less, like 20 days after the previous event, the session window [will extend and cover..] extends and covers that as well. If there are no new events for the next 30 days, the session window [will close..] closes and is emitted."

Changed

5. I had to scroll up to remember what input events look like in the later examples. It would be nice to include a screenshot of the input events to the right of the nice bar charts, then these screenshots can be easily included by other tutorials/talks.

I actually ended up inlining the data on each snippet. It makes each sample a little more self contained, and simplified some indirection. It also makes it easier for people to modify the inputs and see how it affects things.

@aaltay sorry for the delay on this one, but comments have been addressed and should be ready for review.

R: @pcoet

FYI: @rosetn