gmailに日時指定送信できるようになるらしい！
ま、今でもカレンダー通知使えるから
んー状態だけど、間違いは防げるので
これはこれで良いかも。

記事
https://forest.watch.impress.co.jp/docs/news/1177942.html
article

It seems that you will be able to send date and time to gmail!
Well, I can still use the calendar notification
Although it is a state, since a mistake can be prevented
This may be good.

Updates
https://gsuiteupdates.googleblog.com/2019/04/write-now-send-later-with-schedule-send.html