Can anyone interpret this sentence in a tenacy agreement please?

[MossyBottom]

^The Tenant may bring the tenancy to an end at, or at any time after, the expiry of the fixed element by giving to the Landlord at least one month’s written notice stating that the Tenant wishes to vacate the
Property. A letter will suffice to implement this sub-clause. While the tenancy is periodic the one month’s written notice must expire the day before a Rent Due Date^

While the tenancy is periodic the one month’s written notice must expire the day before a Rent Due Date.

DS had a 6 month tenacy and when that expired it became a monthly rolling contract. He's looking to move. His rent falls due on the 18th of the month.
Does this mean he can only give notice on 18th of any month, the day his rent is due?

He can give notice whenever he likes, but the one month would only start on the 18th. So he could, for example, give notice on the 5th October but the one month would start from the 18th with the tenancy ending 17th November

Thank you, that's a clear explanation. It seems likely he'll have to have a bigger overlap than he would have liked.

Not to mention the contract but also negotiate with the landlord to release the tenant early if someone else wants to move in sooner.
Maybe they'll say yes and that's even better!

your ds needs to give at least one month's notice. so he could give notice today, but the tenancy would expire on 17 November.

as pp said, most landlords will be happy to negotiate out of this clause if there is an incoming tenant ready to move in sooner. this just protects them from going too long without a tenant.

The landlord would have the expense of re-letting, it's EA managed, but definitely worth a try as I suspect he could re-let for quite a lot more now.