get file names only ... sorted by modification day
find + sort + cut approach:
find . -regex ".*/[0-9.]+" -printf "%T@ %f\n" | sort | cut -d' ' -f2 %T@- File's last modification time, where@is seconds sinceJan. 1, 1970, 00:00 GMT,with fractional part%f- File's name with any leading directories removed (only the last element)
To sort in descending order:
find . -regex ".*/[0-9.]+" -printf "%T@ %f\n" | sort -k1,1r | cut -d' ' -f2