Can we say Aameen to our own Duas and Duas made by others? – Sheikh Assim Al Hakeem

Is it prohibited to pray during first 15 to 20 minutes of sunrise and last 15 to 20 minutes of the day just beforesunset Also during the time the sun is exactly at midday. My question is whether one could pray voluntary prayers during these times. As it is usual for people go to mosque just before sunset or mid day and do masjid prayer at these times.