Never feel that one has to meditate at a specific time for a specific time period. A teacher that mandates students to meditate for a certain time at specific times can be questioned and even disobeyed – in my view.
Meditation is not a bootcamp.
One does not improve by force.
It is about gradually progressing and inclining the mind. Enjoying meditation.
Forcing oneself, or having a schedule to mandate meditation may leave the mind shaken up and may cause aversion to meditation.
Kindness and not harshness should be developed.