Google Flights can watch the airfare for your actual travel dates.

If the wedding is on Saturday, a cheaper flight the following Tuesday isn't much help. I'd set a price watch for the trip I can actually take, then close the search tab. Google's existing Flights guide lets you track a route for specific dates, or select particular flights and track those. Choose your airports, dates, ticket count, cabin and stops, then turn on Track prices. Google says it can email you when the tracked price changes significantly. Use ‘Any dates’ only if you really can move the trip: that option watches for a significant drop in the route's minimum price over a month, and can send regular best-price emails even without a big drop. For a fixed family visit, I'd stick to the actual dates rather than give myself more deals to sort through. You can turn the emails off or remove the watch at google.com/travel/flights/saves once you've booked. This is a documented option, not a fare-saving result I've measured; an alert isn't a promise of the lowest possible price.