A 'banyan day' is typically a day where unexpected things happen and end up taking longer than expected. Synonyms for this phrase include 'crazy day', 'hectic day', 'long day', 'never-ending day', 'frustrating day', 'challenging day', 'unpredictable day', 'chaotic day' and 'unmanageable day'.
These synonyms all reflect the same sentiment - that it's a day where things aren't going according to plan, and it's easy to get overwhelmed and frustrated. However, while a banyan day might seem like a negative thing, it's worth remembering that these days can also be incredibly rewarding. By pushing through the chaos and uncertainty, you'll emerge stronger and more capable for it.