(Based on the Motu Propio of Pope Pius XII, March 19, 1957)
The priest (before Mass, whether it be in the morning, afternoon, evening or midnight) and faithful (before Holy Communion) must abstain for three hours from solid foods and alcoholic beverages, and for one hour from non-alcoholic beverages (like coffee, milk, tea, juice, etc.). Water can be taken anytime.
The infirm (even if not bedridden) may take non-alcoholic beverages and that which is prescribed medicine (either in liquid or solid form) before Mass or Holy Communion without any time limit.
* For any questions or clarifications, please discuss with the priest.