The deals you're likely going to close before the end of the month (or any selling cycle) are already leaning your way. If they're going to close this late in the game (let's say there's just a couple days left in the month or quarter), they've pretty much already made up their mind...except for that one last objection or two.
Do you know what those objections are? Do you know specifically what's keeping them from making a positive step forward?
Is it lack of clarity on the value and ROI of the purchase? If so, have you left the issue of value translation in the prospect's hands, or have you proactively addressed, defined and calculated the positive future of going with your product or service?
Is it getting that last decision-maker on board? If so, how well do you already know that decision-maker, what he/she cares about, and how best to either translate value for them, or isolate and address their specific objections (which may be different from that of your direct buyer)?
Is it a budget issue? If so, without making a concession on price, how do you make it easier for them to buy now? Can you get creative with your own finance team to improve the terms of the deal without making it cheaper? Can you define a specific ROI for whomever holds the purse-strings to make it a win for their objectives as well?
If the opportunities in your sales pipeline with a month-end or quarter-end close haven't yet decided if they need what you're selling, closing them in the next couple days (especially for a complex or considered sale/purchase) might not be realistic. But if you know they already want it, that they already need it and see the value to their business, it's your job to create and execute a specific objection-handling effort that strategically and specifically eliminates the last barrier to success, for both you and your customer.