As of May 2020, users are now able to schedule twitter posts through the Ads section of the Twitter dashboard. Scheduled Tweets can either be organic or Promoted, but users will need a Twitter Ads account to use the scheduling feature.
Step 1: Log in to your Twitter Ads account and select the Tweet Composer option under the Creatives tab.
Step 2: Write out your Tweet, add any media you want to it and uncheck Promoted only if you want this to be an organic Tweet on your feed.
Step 3: Select the drop-down menu right next to the Tweet button at the top right of your screen and click Schedule.
Step 4: Select the date and time when you want your Tweet to go live.
Step 5: Click Schedule to finish the scheduling. Check the Create another option if you want to immediately schedule a new Tweet.