Words for a real moment
What to say when someone has had a rough day
A rough day rarely needs a grand solution. A short acknowledgement and one easy offer can feel much more human.

Words you can use
A ready-to-send version
That was a lot for one day. I can listen for ten minutes or simply send a quiet hello. You do not need to explain anything, and no reply is required. If today is not right, that is completely fine.
A useful approach
Start with one honest sentence about the day they have had.
Offer a short message, a ten-minute call, or quiet voice-note company.
Leave the offer open for today; do not send another message until tomorrow.
Make it fit your person
Change the relationship, timing and tone
No name is needed. Optional details are not stored.