Can my customers search flexible dates on my portal to find the cheapest day to fly?

Yes, a flexible date search is normally possible, though how far it goes depends on which flight suppliers are connected to your portal. The common version is a search that looks at a few days either side of the date your customer typed, so they can see whether leaving a day earlier or returning a day later brings the fare down. A full calendar view across a whole month is heavier work, because the portal has to ask the supplier for many date combinations at once, and not every flight source will answer that kind of request.

The difference usually comes down to where the fares are coming from. Content from the big global distribution systems tends to support date range searching well, because it was designed with that in mind. Low cost carriers and some direct airline connections often answer one date at a time, so a month view for those can be slower, incomplete, or simply unavailable. If one particular airline matters a lot to your business, test it on your own portal before you promise the feature to customers.

There is also a speed trade off to keep in mind. Every extra date is another question to the supplier, so a wide flexible search takes noticeably longer to come back, and customers do not wait patiently. Many agencies find three days either side is the practical sweet spot, and keep a wider cheapest month view only for the routes they sell most often.

Take a look at which flight sources are switched on for your portal, run a flexible search on your two or three busiest routes, and then decide whether a wider date range is worth the extra waiting time.