“Please try and be on time tomorrow.” It’s hard to know where “try and” came from. If you think about it, the expression seems to direct a person to do two things: (1) try, and (2) be on time. The grammatical error is minor; the main problem is that the construction simply does not say what we think it most likely means.
“Try” (whether in the sense of “to expend effort” or “to test”) is a transitive verb. (In the “try and” construction, there is no object for “try.” That is the minor grammatical fault.) As a transitive verb, “try” must have a direct object. This may be a noun or pronoun (“Try this song”), an infinitive (“Try to sing!”) or a gerund (“Try singing”). When there is no explicit direct object, as in “Try again,” the direct object (perhaps “it”) is understood: it is not “trying” if one is not “trying something” or “trying to do something.”
The most recent edition of Fowler’s English Grammar and a couple of dictionaries are more charitable than I would be about this expression. They call it “an idiom.” You call any non-standard usage an “idiom” when you give in and say, “well, it doesn’t follow the rules, but we all can live with it.” There’s a fine line between idiomatic and idiotic. The permissive crowd also adds the caution that “try and . . . ” should not be used in formal speech. Well, I should think not! Try not to say “Try and . . . .”
And one other thing: “Try” is widely used as a noun, as in “The old college try” or “Give it a try.” This used to be considered wrong. The noun form of “try” is “trial,” just as the noun form of “deny” is “denial.” As a noun it started out in the sense of “assay” or “test,” but migrated to “attempt.” It has been nominalized for so long and so widely that today it is accepted as a noun, even in formal writing. If you are in an ultra-conservative mood, you might decide to label it a neologism and avoid using it, but that is a losing battle.