Unless you've been living in the cloud recently you cannot have failed to note that 750,000 public workers, including teachers, have called what is in effect a general strike for 30 June over the issue of proposed changes to their pension scheme.
Whilst this action may be called off you need to plan for it going ahead, especially if you are a service provider or in anyway involved with just in time deliveries.
You need to establish which schools and employees are going to be affected - maybe there's 'group' action that can be taken that will benefit all including some form of 'creche'.
With the likelihood being that employees with children will all be affected, employers are going to have to be flexible when considering requests for time off or holidays. Whilst employment legislation provides protection for time off for domestic emergencies - including the provision of child care - it only applies when the situation is unplanned and unforeseen. That said, with the breadth of support for the strike nationally it would be very harsh for an employer to penalise an employee in this circumstance.
Employers should be alert to employees using the strike action to take a day off though.