Mnemonic Device :

• Dra Sid An Syn (i.e. a person’s name Drasid Ansyn)

Explanation: The period of time of the moon revolving around the earth in increasing order.

• Draconic (27.2 days)
• Sidereal (27.3 days)
• Anomalistic (27.5 days)
• Synodic (29.5 days)