If I buy VHYL now will I get the dividend at the end of the month, or do I have to own it for a certain period of time?

As the title says really, if I buy VHYL now will I get the dividend at the end of the month, or do I have to own it for a certain period of time to qualify?

If not, what's to stop loads of people piling in towards the dividend date, then putting their money elsewhere till the next time a dividend is due?

Sorry if this is a basic question. New to all this.