The Yizkor memorial prayer is recited four times a year at synagogue services, including on Shavuot. Practices for length of holiday observance vary between denominations, so please check with your rabbi or synagogue to confirm this information. For those who observe two days of Shavuot, the Yizkor service is held on Thursday, May 16th. For those who observe one day of Shavuot, the service will be on Wednesday, May 15. A yahrzeit candle is traditionally lit the evening before.
Please see our website for a full calendar of Yizkor dates (based on 8-day observance).