Opinion by
Mr. Justice Mitchell,When this case was first here the appeal was quashed because it nowhere appeared that any exception had been taken in the court below, or that the charge had been approved by the judge or filed by his order: 171 Pa. 500. Subsequently the learned judge who tried the case, with the consent of counsel of both parties, approved the charge and directed it to be filed of record. This though not so expressed in terms, must be considered as a filing nunc pro tunc, and the case is therefore regularly before us, as if the exceptions and the charge had been taken and filed at the trial.
Notwithstanding the bulk of the record there is very little in the case but a question of fact. The issue was upon a judgment opened to determine whether the previous notes in the hands of the plaintiffs in October, 1891, at the time the defendant gave the ten judgment notes in snit, were included in that settlement. These prior notes being admitted to be due, the court required them to be paid, and then permitted such payment to be set off in the actions on the later judgment notes. These notes were entered up separately, birt the opened judgments were tried together and we shall treat them as a single case.
The burden of proof was on the defendant, not only because the execution of the notes was admitted, but also because in the order opening the judgments the court had directed the issue to be made by the plea of payment, and the evidence to be confined to that matter as alleged in the petition and answer. This *474consideration does away with the force of the principal assignments of error. The fourth which is the most important in the amount involved by it, relates to the deposit slips. These under the circumstances of the case were evidence of deposits which should be credited to the defendant in making up the account, but they were not conclusive, and had to go to the jury with the explanation of the plaintiff that they were accidentally misdated, and were duly credited in the account at their proper dates. The court submitted them in this way, and there was no error in so doing.
The sixth assignment relates to the refusal of the plaintiff’s points followed by a substantial affirmance. They were refused because of the form of expression, which as the learned judge said seemed “ to eliminate from consideration both the corroborating circumstances, and the matter of the credibility of the witnesses,” but in substance they were correct statements of the burden of proof, and there was no'error in so affirming them.
The remaining specifications of error are to the expressions of opinion by the judge on parts of the evidence. The case was one which justified the judge in commenting on the evidence with more than usual- particularity. It was out of the ordinary juror’s experience, involving very loose and irregular banking transactions extending over a number of years and running into large figures in which a jury might easily get bewildered. The judge assisted them by pointing out clearly the bearing of the various items of evidence, and if he sometimes allowed his own opinion to be seen, we do not find that he trespassed at any point on the jury’s province to decide the facts for themselves.
In regard to the calculation of interest the strict legal rule is. certainly to compute it according to the actual time, three hundred and sixty-five days to the year. But it is the custom in banks and some other kinds of business where calculations of interest are required frequently, to compute it for the sake of convenience at thirty days to the month and twelve months to the year. The result when calculated for a year is of course the same, the exact six per cent on the sum involved, and the difference in amount for fractions of a year is usually so small as to be unimportant. The present transactions were with a *475banker, and in tbe absence of any evidence to show that either mode of computation was specifically agreed upon by the parties,' it was not error for the judge to assume that the mode usual with bankers was to be pursued, though it is not the ordinary legal rule.
Judgment affirmed.