calculating a duration variable

[Jordan Kennedy]

Hi all:

I have two date variables in the following format: hh:mm:ss:ss. The
first variable represents bedtime and the second variable represents
wakeup time. I would like to create a numeric variable that represents
total hours slept. So for example, the first variable has a value of
21:00:00:00 and the second variable has the value 4:00:00:00. I would
like the new duration variable to reflect the value of 7. What's the
best way of doing this? Thanks!

Jordan

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[Maguin, Eugene]

Jordan,

Suppose bedtime and wakeuptime are time10.1. True??
Sometimes bedtime and wakeuptime are different days but assumed less than 24 hours apart.

Do if (bedtime lt wakeuptime).
+  compute sleep=wakeuptime-bedtime.
Else.
+  compute sleep=time.hms(24,0,0)-bedtime+wakeuptime.
End if.
Format sleep(time8).

Gene Maguin


-----Original Message-----
From: SPSSX(r) Discussion [mailto:[hidden email]] On Behalf Of Jordan Kennedy
Sent: Tuesday, March 06, 2012 3:58 PM
To: [hidden email]
Subject: calculating a duration variable

Hi all:

I have two date variables in the following format: hh:mm:ss:ss. The
first variable represents bedtime and the second variable represents
wakeup time. I would like to create a numeric variable that represents
total hours slept. So for example, the first variable has a value of
21:00:00:00 and the second variable has the value 4:00:00:00. I would
like the new duration variable to reflect the value of 7. What's the
best way of doing this? Thanks!

Jordan

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[Bruce Weaver]

Look at the Date and Time Wizard in the Transform menu.  

Do you also have the dates stored?  They would be helpful, as the wake-up time may not always be on the subsequent day (e.g., if someone retires after midnight).  If you do have both date and time variables, they can be combined into datetime variables.  For example:

data list list / datevar (date11) timevar(time11).
begin data
5-Mar-2012 21:00:00:00
6-Mar-2012 4:00:00:00
end data.

numeric dtvar (datetime).
compute dtvar = datevar + timevar.
list.

OUTPUT:
    datevar     timevar                dtvar

05-MAR-2012    21:00:00 05-MAR-2012 21:00:00
06-MAR-2012     4:00:00 06-MAR-2012 04:00:00


With two such date-time variables (for bedtime and wake-up time), you could use the DATEDIFF function to get the difference in whatever units you want.  Look it up in the fine manual.

HTH.

Jordan Kennedy wrote

Hi all:

I have two date variables in the following format: hh:mm:ss:ss. The
first variable represents bedtime and the second variable represents
wakeup time. I would like to create a numeric variable that represents
total hours slept. So for example, the first variable has a value of
21:00:00:00 and the second variable has the value 4:00:00:00. I would
like the new duration variable to reflect the value of 7. What's the
best way of doing this? Thanks!

Jordan

=====================
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[David Marso]

data list list/BT (Time11) WU (Time11).
begin data
12:00:00:00 21:00:00:00
21:00:00:00  4:00:00:00
07:00:00:00 12:00:00:00
end data.
list.
COMPUTE slept = WU-BT + (WU<BT)*86400.
FORMAT slept (Time11).
list.
<quote author="Jordan Kennedy">
Hi all:

I have two date variables in the following format: hh:mm:ss:ss. The
first variable represents bedtime and the second variable represents
wakeup time. I would like to create a numeric variable that represents
total hours slept. So for example, the first variable has a value of
21:00:00:00 and the second variable has the value 4:00:00:00. I would
like the new duration variable to reflect the value of 7. What's the
best way of doing this? Thanks!

Jordan

=====================
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