Letter wording: I am writing regarding our [meeting/discussion] on [date] when I informed you that the Company would be unable to accommodate your request of [date] to take parental leave from [date] to [date], because [reason].

[At this meeting/during this discussion] I informed you that, in the circumstances, the period of parental leave could be postponed for not more than six months from the date on which you wanted to start it.