Twitter just announced that you can now schedule tweets via Twitter Web.
YOU CAN SCHEDULE VIA TWITTER WEB
A little calendar icon will appear on the bottom row of icons on the bottom of the compose window when composing a tweet.
Click on it and you can specify when you want the tweet to be sent or posted.
Back in November 2019, Twitter said it was “experimenting” with the new feature. If you didn’t have access to that experiment, you’d have to use tweetdeck or any third party services that supported the feature.
You can also save your draft tweets in the web app. However, drafts written on Twitter’s mobile app won’t sync to the web.
— Twitter Support (@TwitterSupport) May 28, 2020