If you are going to contact employers that have just run classified ads over the weekend, Monday is magic. All weekend they have been thinking about the position (I'm not kidding!) and how to fill it. If you are the solution, let them know right away. Even if they just ran an ad on Sunday, be ready to be their quick solution. Mailed resumes will not start arriving until at least Tuesday or Wednesday and e-mails may not be read immediately, so personal visits or well-placed phone calls will have virtually no competition. Employers that run ads and job postings usually have a position that needs to be filled now, often due to a resignation on Friday of the previous week. For job postings, it would be the day the job posting is listed. And most employers that run ads and job postings would love to avoid the oncoming "resume onslaught" that awaits them later in the week, if they can avoid it. Be there with a quick solution to the problem.