When is the best time to….

When a client sits with me to plan a trip, I usually get at least one question that begins, “When is the best time to … ” Having been in the travel business for over a decade, and having traveled the world with my three kids, I have considered a lot of these clock and calendar questions. Today, I offer 13 timely tips to make your travels go more smoothly.

When is the best time to …

1. Take off in an airplane?

Answer: Between 6 a.m. and 7 a.m. on a Tuesday or a Saturday. According to the U.S. Department of Transportation, Tuesday and Saturday have the highest percentage of on-time flights — 82 percent on both days. Another good reason to fly on Tuesday is that you avoid crowds of vacationers, who travel on the weekend, and business travelers, who fly at the beginning and end of the work week. And the earlier the departure the better, because there is less chance of getting caught in delays caused by problems with earlier flights and weather.

2. Go to the top of the Empire State Building?

Answer: At night, in the middle of the week. The building is open until 2 a.m. on most days, and the nighttime views of Manhattan are spectacular! Crowds are smaller late at night than during the day, and midweek crowds are smaller than weekend ones. As many as 16,000 people visit the observation floors on a busy day, and each one has to stand in three separate lines: for security, tickets and elevators. The wait can range from 30 minutes to three hours — and you thought the airports were bad! Best bet: Call ahead to check on the wait times (212-736-3100).

3. Take in the lights of Broadway?

Answer: Tuesday or Wednesday nights have the smallest crowds of theatergoers. The months of January through April are especially good bets because you miss the holiday crowds and can catch shows before the Tony nominations are announced in mid-May. For late tickets, check in directly with the theaters. They hold seats for visiting celebs (like my crush Paris Hilton) and will release them up to a week before the show, and they are usually fantastic seats. You can also get same-day tickets from TKTS; its kiosk in the middle of Times Square opens at 3 p.m. and tickets to most shows that night can be had for $40 to $50, Cash only. Remember, most theaters are “dark” on Mondays (that means “closed”!)

4. Haggle with a street or market vendor?

Answer: At the end of the day. Shopping right before vendors pack up their wares and tally the day’s profits can profit you; in fact, you can probably name your price. The less they have to haul away, the better. And here’s a useful tip: The wares change often, so if you see something you like, get it. It might not be there when you come back later.

5. Score a reservation at the hottest restaurant in town?

Answer: Three to six months ahead of time will pretty much guarantee you a table. Some restaurants take reservations only one or two months in advance; call to find out, and then mark your calendar accordingly. If you are having trouble, ask for the maitre d’ and calmly and confidently explain that you are calling on behalf of Paris Hilton … No, no no, explain that it is a special occasion and you would like to experience all the great things you have heard. Usually, the restaurant will accommodate you. Get the reservations agent’s name and be sure to give a tip and hearty “Thank you!” when you arrive. Your travel agent will often have the connections to make this happen for you, as well. Just ask!

6. Land a standby seat?

Answer: Planes are less crowded on Tuesdays and Wednesdays. Check with your travel agent, or log on to the airline’s Web site before heading to the airport and check the availability. If there are empty seats, most airlines will accommodate you. Caution, some airlines will charge a standby fee (but no increase in the fare) — greedy airlines!

7. Visit Disney World or Disneyland?

Answer: When school is in session. The busiest times, by far, at Disney theme parks are during school vacations, especially over Christmas and during spring breaks. If you can go when school is in full swing, you’ll find significantly shorter lines. One of my most memorable trips to Disney World was the week following Thanksgiving. The park was decorated for the holidays, the temperature was great, and the crowds were nonexistent.

8. Visit popular tourist destinations?

Answer: It depends. Every destination has a high season and a low one. High season tends to be harmful to your wallet, and low ones tend not to offer the experience you had in mind. So determine the destination’s “shoulder season” (not sure where this term comes from, but that’s what the in-between of “on” and “off” season is called) Typical shoulder seasons offer lower prices, fewer tourists, just OK weather … you get the picture. Here are the shoulder seasons of some popular destinations.

• Las Vegas: May and September
• Florida: Late April, May, Late August, October
• New York City: April, September, October
• Los Angeles: January, April, May
• Caribbean: July, August, November
• Colorado: June
• Hawaii: September, October, November, January
• Canada: April, May, September, October
• Mexico: February, Early December
• Europe: April, Early May, September, January

9. Visit a museum?

Answer: After 1 p.m. on a school day. Tour groups visit in the morning, so by early afternoon they’re gone and you’ll pretty much have the run of the place. Keep an eye on the weather; museums tend to be people magnets on rainy days. And if you don’t have holiday plans and the museum is open, head on out; chances are it will be empty.

10. Buy a new suitcase?

Answer: April, May or June. Suitcases are like clothes: They have seasons — though, sadly, their shows are nothing like the Victoria’s Secret show. Early spring and summer are good times for deals on last year’s models (the luggage models not the Victoria’s Secret models). If you travel a lot, or plan to, good luggage (I recommend Briggs & Riley) is a good investment. It will cost a bit more, but it will pay dividends in the long run as it will last forever and possibly offer a lifetime guarantee.

11. Take that perfect snapshot?

Answer: Early morning or late afternoon. The first and last hours of daylight offer the most flattering light. Professional photographer Ned S. Levi, of Philadelphia, calls these the “magic hours.” “During early morning and late afternoon hours, when the sun is low on the horizon, the light is orange and gold, and gives photographs the warmth and glow we see in front a fireplace during a romantic evening rendezvous,” Levi says. The worst time to shoot: between 10 a.m. and 2 p.m., when the sun casts shadows from above (although, according to Levi, these times can be excellent for monuments and buildings).

12. Visit the Grand Canyon?

Answer: Since we are looking for perfect photos. The last two weeks of August. A lot of families go back to school in the middle of August, and the foreign visitors are often told not to come until after Labor Day, so the end of August is perfect. Temperatures are also cooler than during the brutal part of the summer, and it rains more often, which also helps keep things cool. The ideal time is two to three hours before sunset. The final moments of the sun dropping below the horizon are great, but the hours leading up to it, when the setting sun is bouncing off the walls of the canyon, are truly spectacular. See tip 11!

13. Renew your passport?

Answer: If you had asked me this question this time last year, I would have said 1980, but the State Department seems to have gotten its act together after months of vacation-ruining delays. According to the Bureau of Consular Affairs, which issues passports, the best time to renew is November. Passports usually take six weeks to process; if you need yours sooner, pay for the expedited service and have it in “about” two weeks. Most passport applications can be processed at most post offices. If you don’t have a passport, just apply for one now. You will need one at some point and it is a universal identification — and at $10 a year, it is a cheap one at that!