9.7. Date & Time
Your Mac's conception of what time it is can be very important. Every file you createor
save is stamped with this time, and every email you send or receive is marked with this
time. As you might expect, setting your Mac's clock is what the Date & Time pane is all
9.7.1. Date & Time Tab
Click the Date & Time tab. If your Mac is online, turn on "Set date & time
automatically," and be done with it. Your Mac set sits own clock by consulting a highly
accurate scientific clock on the Internet. (No need to worry about Daylight Saving Time,
either; the time servers take that into account.)
Tip: If you have a full-time Internet connection (cable modem or DSL, for example), you
may as well leave this checkbox turned on, so your Mac's clock is always correct. If you
connect to the Internet by modem, however, turn off the checkbox, so your Mac won't
keep trying to dial spontaneously at all hours of the night.
If you're not online and have no prospect of getting there, you can also set the date and
time manually. To change the month, day, or year, you can click the digit that needs
changing and then either (a) type a new number or (b) click the little arrow buttons. Press
the Tab key to highlight the next number. (You can also specify the day of the month by
clicking a date on the minicalendar.)
To set the time of day, use the same technique—or, for more geeky fun, you can set the
time by dragging the hour, minute, or second hands on the analog clock. Finally, click
Save. (If you get carried away with dragging the clock hands around and lose track of the
real time, click the Revert button to restore the panel settings.)
GEM IN THE ROUGH
Your Free Time-Difference Calculator
You can use the Time Zone tab of Date & Time to calculate the exact time
difference between any two points on earth. To do this, you must have the Time
Zone pane open and your menu bar clock turned on and set to View as Digital.
(See the discussion of the menu bar clock in this chapter.)
To calculate a time difference, make a note of the current time shown in the
menu bar, with the Time Zone correctly set to your own zone. Now click your
way across the Time Zone map. With each click, notice that the time in the
menu bar changes, updating itself as you cross from time zone to time zone. By
comparing the original time on your menu bar with the new time that appears
when you've finished clicking, you can easily determine the time difference.
(On the other hand, you can always open Dashboard, described in Chapter 5,
and just open two copies of the World Clock widget—one set to each city.)
Tip: If you're frustrated that the Mac is showing you the 24-hour "military time" on your
menu bar (that is, 17:30 instead of 5:30 p.m.)—or that it isn't showing military time when
you'd like it to—click the Clock tab and turn "Use a 24-hour clock" on or off.Note,
however, that this affects only the menu bar clock. If you'd like to reformat the menu bar
clock and all other dates (like the ones that show when your files were modified in list
views), click the Open International button at the bottom of the Date & Time pane. Once
there, click the Formats tab. There you'll see a Customize button for Times, which leads
you to a whole new world of time-format customization. You can drag elements of the
current time (Hour, Minute, Second, Millisecond, and so on) into any order you like, and
separate them with any desired punctuation.
9.7.2. Time Zone Tab
You'd be surprised how important it is to set the Time Zone for your Mac. If you don't do
so, the email and documents you send out—and the Mac's conception of what documents
are older and newer—could be hopelessly skewed. Teach your Mac where it lives using
the Time Zone map, as shown in Figure 9-6.
Figure 9-6. To set your time zone the quick and dirty way, just click on a section of
the map to indicate your general region of the world. You'll see the vertical stripe
showing your time zone.
If you want to teach the Mac more precisely where you are in that time zone, now
use the pop-up menu to specify the closest big city in that time zone. (Or, instead of
using the pop-up menu with the mouse, you can also highlight the text in the Closest
City box. Then start typing your city name until the Mac gets it.)
9.7.3. Clock Tab
In the Clock pane, you can specify whether or not you want the current time to appear, at
all times, at the right end of your menu bar. You can choose between two different clock
styles: digital (3:53 p.m.) or analog (a round clock face). You also get several other
options that govern this digital clock display: the display of seconds, whether or not you
want to include designations for a.m. and p.m., the day of the week, a blinking colon, and
the option to use a 24-hour clock.
Tip: At the bottom of the dialog box, you'll find a feature called "Announce the time." At
the intervals you specify, the Mac can speak, out loud, the current time: "It's ten o'clock."
If you tend to get so immersed in "working" that you lose track of time, Mac OS X just
removed your last excuse.
And by the way, your menu bar clock always shows the current time. When you need to
know today's date, just click the clock. A menu drops down revealing the complete date.
The menu also lets you switch between digital and analog clock types and provides a
shortcut to the Date & Time preferences pane.
Tip: This one's for Unix geeks only. You can also set the date and time from within
Terminal (Chapter 16). Use sudo (Section 220.127.116.11), type date yyyymmddhhmm.ss, and
press Enter. (Of course, replace that code with the actual date and time you want, such as
200804051755.00 for April 5, 2008, 5:55 p.m.) You might find this method faster than
the System Preferences route.