Some variation is allowed. The verity of the hours needs to be respected. PetraG gives a good example of monastic practice (where Prime still is used; it is very rare in monasteries now unless using the pre-Conciliar Office)
I have been doing this
9 A.M Morning
12 Noon Daytime
6 PM Evening
Before bed Night
But was not sure if it was right
Your hours are fine if it fits your personal schedule; they respect the “verity” of the hours. For myself, I find Lauds (Morning Prayer) a bit late at 9 am, but it is still respecting “morning”.
My own summer schedule at the moment is:
Invitatory and Lauds (Morning) 6 am (I’m an early riser)
Mid-day at either the hour of Terce (9:45 am in my case, same as the abbey I’m associated with), or the hour of Sext (noon) depending on whether or not I have outdoor activities planned;
Vespers (Evening) 5pm
Compline: just after I go to bed (I pray it in bed)
Chapter (reading of the next day’s chapter of the Rule of St. Benedict and of the next day’s Martyrology) after Compline
Office of Readings (vigils) after Chapter.
In the secular Office it is more usual make Compline the last hour of the day, but in the monastic tradition, when Vigils (Office of Readings) is anticipated the previous evening, it is prayed
after Compline. The reason is because the Office of Readings retains its nocturnal character in the monastic tradition. Compline signals the start of the night, so the Office of Readings should be prayed
in the night, even if it means just a short time after Compline. I know monasteries that do this for this reason. As I’m a Benedictine secular oblate, I follow the monastic praxis.
Otherwise, the more usual times for the OOR are between Vespers and Compline, or in the early morning before Lauds. But you can licitly pray it any time during the day.
Note I’m inclined to use the more traditional nomenclature, the LOTH books I have used them (French and Latin)
Lauds = Morning Prayer
Terce, Sext and None = mid-day prayer (if only doing one mid-day hour)
Vespers = Evening Prayer.
I like regularity in my hours but the reality is that Compline tends to be variable since I don’t always go to bed at the exact same time.