Related Clues:

• Take part in cruise, as on a liner during summer, perhaps?
• Opportunely
• Timely, advantageous
• Like some temp workers
• Copper goes into one, with perfect timing
• A boy dives into lock, depending on the time of year
• Happy pop fans or what they're likely to be listening to
• Like Santa's job
• Working for Christmas, say
• As if planned to happen just then
• When to enter
• At the proper moment
• Precisely when expected
• As planned
• At the right moment put chalk here