The phrase "certain times" refers to specific or particular moments or periods. It implies that there are specific occurrences or situations being discussed, rather than referring to all times in general. Full definition
That setup allowed the scientists to test whether different species were attracted only at certain times of day. (sciencedaily.com)
You must mention offer at time of scheduling appointment as there is limited availability for these appointments on at certain times of day. (veterinarians.com)
In fact it is not something that can happen within minutes or within certain time period after birth. (attachfromscratch.com)