Reducing to a 4 day week -impact on redundancy calculation?

[user1496146479]

Based in Ireland.
Considering taking parental leave one day per week, but not sure how this would impact any future redundancy calculation?
If made redundant while still taking parental leave, would the calculation be based on 4 days or 5 days?

Have googled, but keep getting results for 'Parents Leave' instead of 'Parental Leave'

Don't want to ask HR yet, as I'd like to have my ducks in a row first.

Anyone got any ideas?
Thanks

If you are on protected leave, it's your normal working hours which would be used for redundancy calculation. But 1 day a week is unlikely to be allowed by many employers.

www.citizensinformation.ie/en/employment/employment-rights-and-conditions/leave-and-holidays/parental-leave/

Thanks my employer does allow it this way, or at least there are lots of others doing similar. Some even taking 8 hours per week over multiple days.
Just trying to weigh it up