Better late than never
To arrive or do something later than expected isn't good, but it is better than not at all.
This proverb is often expressed with a degree of sarcasm, apparently saying something positive but in fact merely remarking on someone's lateness. A teacher might say it to a child arriving late for school, for example. Geoffery Chaucer appears to have been the first person to have put the proverb into print, in The Yeoman's Prologue and Tale, Canterbury Tales, circa 1386:
For bet than never is late. [Better than never is late.]
See also: the List of Proverbs.