This would be a good day to finish the holiday mailing you’ve planned. Doug Morrow, senior manager for district post-office operations, says he has ample experience to let him predict an all-time heavy volume of mail this coming Monday.Looking at this date from a year ago, Morrow says he can predict accurately what will happen this time of the season. It’s not a date so much as a time of the year and the habits of mailing customers that can let Morrow accurate predict the future, and the long lines coming Monday to a post office near you. Historically, he says the volume peaks on the Monday around December 16th, because of its spot between Thanksgiving and Christmas, and because people spent the weekend wrapping things they go out and mail that Monday. Because of the short time between the two holidays this year, Morrow says you’ll find even more people in front of you in the post-office line.He says this kind of volume is more than they can sort and get on the trucks, so get out and mail your cards Saturday or Sunday, don’t wait till Monday. If you are mailing to foreign countries, there is a cutoff date, but you’re also advised to use Priority Mail service if you want holiday arrival for anything you send after this Saturday.