I can add some more context here. Your device went offline about 4:30PM on the 29th. We do actually store or buffer irrigation events when the device disconnects from WiFi and is able to reconnect. I believe in your case the device disconnected from WiFi and after 23 hours of being offline the device will reboot itself to force a reconnect to WiFi.
When a device is rebooted we do lose the buffered irrigation data since it is not placed into permanent storage on the device. The reboot is a last ditch attempt to force the Iro back online, which in this case it looked like it worked. This is normally not needed since most devices reconnect within a few minutes.
If the Iro is offline for at least 24 hours you will receive an email at roughly 1am (that's when the job runs) to let you know the device is offline. Your device came back online at 11:43PM on the 30th, hence no email.
We do show when a device is power cycled but do not show WiFi connects/re-connects since it would be a lot of noise. We actually did try exposing them and our support team spent all their time answering questions regarding that data.
Like I stated above in most cases this data does get sent to the cloud. Your device did go offline for quite some time hence no data. We try to cover these scenarios but there are some that we just don't handle at the moment. In general your device looks like it is staying online. If you do see issues regarding offline our support team has a few tricks that could help. I don't know what kind of router you have but a newer router goes a long way to helping with connectivity.
Hope this helps.