You are most probably familiar with the discussion around 'important' and 'urgent' and that we tend to be very good at doing the urgent stuff, less so the important stuff.
When people consult in me and ask how to improve and sharpen their Business English, I always tell them that once a week is nice, but not enough. I tell them that if they really want to give a boost to their English, they should build a weekly/monthly schedule.
For example: on Mondays. listen to podcasts in English, on Tuesdays schedule a lesson with a professional, on Wednesdays watch a TV series but in English (no subtitles), on Thursdays have a 15 min. conversation in English with someone...etc.
And if you are not convinced, watch this short 5 minute video: https://www.youtube.com/watch?v=73Ot80nngvY&t=10s .
And if you are convinced, watch this video, and prepare your weekly/monthly schedule, and you'll find many materials in this blog to help you.
Start with the attached pdf document where you'll find ideas and tips for how to wrap yourself in English.
One day or Day One. You decide.