How to know what time it is? - Page 2

Admiral Halsey · 02-02-15, 01:40 PM

I swear that if you load a game while you're in mid-patrol the game will use local time then.

aanker · 02-03-15, 01:24 PM

SH4 uses base time in-game. I don't know about Mission Editor time however it would be easy to find out.

Each patrol I draw vertical lines on my chart - 15d for every hour, so I know how many hours to add or subtract from base-time depending on where I am. It only takes a few minutes to do, and is very helpful.

I draw vertical lines 7.5d each side of 180d, and every 15d E and W from those lines. The moon-rise & moon-set tables can then be used as well as the Sun tables to plan your attacks etc. There aren't the RW N/S seasonal differences, so the tables are pretty close no matter what latitude or longitude you are on.

I found this so useful I edited the Sun & Moon tables into my F1 Help file.

- Edited spelling - (if you can't spell a word more than one way, you don't know how to spell) ... lol

Happy Hunting!

Gaius Godefridus · 02-11-18, 04:17 AM

I think the base time BT is the time on the naval base, so the Zone Time ZT.

Example:
1941 December 10 - base time 17-15-00
The naval base is Pearl Harbor on 21°20.7'N and 157°58.5'W and is located in the Zone Time GMT-10

Determine Greenwich Mean Time GMT and Local Mean Time LMT on naval base Pearl Harbor

Step 1 - GMT = BT + 10
BT 17-15-00 + 10 hours = 27-15-00 minus 24 = 03-15-00 GMT next day on December 11

Step 2 - LMT on naval base Pearl Harbor = GMT minus arc to time of longitude
157°58.5'W arc to time = 157.975 / 15° = 10.531667 hours
03-15-00 GMT on December 11 minus 10.531667 hours = -7.281667 + 24 = 16-43-06 LMT on December 10

Determine the Local Mean Time at the current position of the submarine

Example:

The submarine leaves Pearl Harbor 1941 December 10 at 17-15-00 base time with course 275° and speed 11kts
and is on December 12 at 17-15-00 BT on position 21°41.4'N and 167°24.2'W.

What is the Local Mean Time at this current position?

Difference between longitude naval base and current longitude submarine in arc to time
157°58.5'W minus 167°24.2'W = -9.4283333° x 4 minutes = -37.713333 minutes
17-15-00 = 17.25 x 60 = 1035 - 37.713333 = 997.28667 / 60 = 16.621444 = 16-37-17 LMT

GMT today referred as UTC is the Coordinated Universal Time based on the Greenwich Meridian
and is valid all over the world.

GMT is very important for the celestial navigation and to determine sunrise and sunset.

LMT is the Local Mean Time based on the current longitude.

I don't know if it is implemented in Silent Hunter 4, that would have to be tested.

I hope, I could help a little bit

Aktungbby · 02-11-18, 10:40 AM

Gaius Godefridus!

Gaius Godefridus · 02-11-18, 12:18 PM

Thanks Aktungbby

aanker · 02-11-18, 02:09 PM

Quote:

Originally Posted by Gaius Godefridus

........ GMT today referred as UTC is the Coordinated Universal Time based on the Greenwich Meridian
and is valid all over the world.

GMT is very important for the celestial navigation and to determine sunrise and sunset.

LMT is the Local Mean Time based on the current longitude.

I don't know if it is implemented in Silent Hunter 4, that would have to be tested.

I hope, I could help a little bit

Yes I am familiar with GMT, UTC, & LMT.

When I sail out of Pearl, I use the method I described above your post and here:

Quote:

I draw vertical lines 7.5d each side of 180d, and every 15d E and W from those lines. The moon-rise & moon-set tables can then be used as well as the Sun tables to plan your attacks etc. There aren't the RW N/S seasonal differences, so the tables are pretty close no matter what latitude or longitude you are on.

I found this so useful I edited the Sun & Moon tables into my F1 Help file.

The resulting time zones determined from my vertical lines are close enough to plan an attack, know what time the sun & moon will rise and set, and the 1941 - 1945 moon phases are also close enough to be used.

For people who expect a planetarium - well, they won't 'get one' and will post lengthily replies telling me that basically I am an idiot for even attempting my method, however my method is is better than not having a clue of what time it is where I am. My method is not close enough for celestial navigation and SH4 itself is not close enough for celestial navigation either.

Despite the few naysayers here and there this method does work for me, I know what time it is where I am, and can plan my actions accordingly. I've shared my method and some are thankful because it works for them too, and I don't waste my time on the negative posts anymore.

For people who expect SH4 to be a precision instrument, they won't find it, but my method is close enough for a game, planning a recon, a supply drop, and an attack. I don't do arithmetic, I just know when I cross one of the lines I drew every 15d I just add or subtract an hour depending on which direction I am going to determine what time it is where I am. So simple - <sigh>

Happy Hunting!

USS Lionfish · 04-01-18, 11:21 PM

Not sure if there's a way to get non-base time.

Sean C · 04-02-18, 02:09 AM

Quote:

Originally Posted by aanker

I draw vertical lines 7.5d each side of 180d, and every 15d E and W from those lines.

This is how actual nautical time zones are laid out. They are unlike civil time zones in that they pay no regard to political boundaries. Each nautical time zone is exactly 15° of longitude from pole to pole and differs from GMT by a number of whole hours. Nautical time zones are typically used once a ship has left the territorial waters of a particular nation.

Here is a chart showing all of the nautical time zones, their phonetic names, hours offset from GMT, starting and ending longitudes, and the longitude upon which they are centered. Notice that there is no "Juliet" time zone. Note also that the "Mike" and "Yankee" time zones (+12h and -12h, respectively) are each only 7.5° wide.

aanker · 04-02-18, 06:27 PM

Thank you Nathaniel B. I'd seen others but never this one.

Happy Hunting!

Sean C · 04-02-18, 08:29 PM

You're welcome! That is a chart I made for my own reference and I hadn't posted it anywhere until now.

LCQ_SH · 04-07-18, 10:02 AM

good question. o.o

Bilge_Rat · 04-20-18, 01:09 PM

although not scientific, you can make an educated guess as to local time just by looking at the position of the sun.

actual local time is irrelevant, what you really want to know is how many hours of daylight or night you have left.

In campaigns, I just make a mental note of when the sun rises or sets each day.

I dont think single missions use "Base time".

02-03-15, 01:24 PM	#17
aanker Pacific Thunder Join Date: Apr 2004 Location: Yellow Sea Posts: 1,896 Downloads: 236 Uploads: 14	SH4 uses base time in-game. I don't know about Mission Editor time however it would be easy to find out. Each patrol I draw vertical lines on my chart - 15d for every hour, so I know how many hours to add or subtract from base-time depending on where I am. It only takes a few minutes to do, and is very helpful. I draw vertical lines 7.5d each side of 180d, and every 15d E and W from those lines. The moon-rise & moon-set tables can then be used as well as the Sun tables to plan your attacks etc. There aren't the RW N/S seasonal differences, so the tables are pretty close no matter what latitude or longitude you are on. I found this so useful I edited the Sun & Moon tables into my F1 Help file. - Edited spelling - (if you can't spell a word more than one way, you don't know how to spell) ... lol Happy Hunting! __________________ " Bless those who serve beneath the deep, Through lonely hours their vigil keep. May peace their mission ever be, Protect each one we ask of thee. Bless those at home who wait and pray, For their return by night and day." Last edited by aanker; 02-11-18 at 02:20 PM.

02-11-18, 10:40 AM	#19
Aktungbby Gefallen Engel U-666 Join Date: Jul 2013 Location: On a tilted, overheated, overpopulated spinning mudball on Collision course with Andromeda Galaxy Posts: 27,842 Downloads: 22 Uploads: 0	welcome aboard! Gaius Godefridus! __________________ "Only two things are infinite; The Universe and human squirrelyness; and I'm not too sure about the Universe"

04-01-18, 11:21 PM	#22
USS Lionfish Nub Join Date: May 2016 Posts: 3 Downloads: 76 Uploads: 0	Not sure if there's a way to get non-base time. __________________ Sometimes all the problems in the world can be solved by turning around.

04-20-18, 01:09 PM	#27
Bilge_Rat Silent Hunter Join Date: Apr 2002 Location: standing watch... Posts: 3,792 Downloads: 344 Uploads: 0	although not scientific, you can make an educated guess as to local time just by looking at the position of the sun. actual local time is irrelevant, what you really want to know is how many hours of daylight or night you have left. In campaigns, I just make a mental note of when the sun rises or sets each day. I dont think single missions use "Base time". __________________

02-02-15, 01:40 PM	#16
Admiral Halsey Best Admiral in the USN Join Date: Apr 2013 Location: USS Enterprise (CV-6) Posts: 1,740 Downloads: 298 Uploads: 0	I swear that if you load a game while you're in mid-patrol the game will use local time then.

02-11-18, 04:17 AM	#18
Gaius Godefridus Nub Join Date: Jul 2016 Posts: 2 Downloads: 155 Uploads: 0	I think the base time BT is the time on the naval base, so the Zone Time ZT. Example: 1941 December 10 - base time 17-15-00 The naval base is Pearl Harbor on 21°20.7'N and 157°58.5'W and is located in the Zone Time GMT-10 Determine Greenwich Mean Time GMT and Local Mean Time LMT on naval base Pearl Harbor Step 1 - GMT = BT + 10 BT 17-15-00 + 10 hours = 27-15-00 minus 24 = 03-15-00 GMT next day on December 11 Step 2 - LMT on naval base Pearl Harbor = GMT minus arc to time of longitude 157°58.5'W arc to time = 157.975 / 15° = 10.531667 hours 03-15-00 GMT on December 11 minus 10.531667 hours = -7.281667 + 24 = 16-43-06 LMT on December 10 Determine the Local Mean Time at the current position of the submarine Example: The submarine leaves Pearl Harbor 1941 December 10 at 17-15-00 base time with course 275° and speed 11kts and is on December 12 at 17-15-00 BT on position 21°41.4'N and 167°24.2'W. What is the Local Mean Time at this current position? Difference between longitude naval base and current longitude submarine in arc to time 157°58.5'W minus 167°24.2'W = -9.4283333° x 4 minutes = -37.713333 minutes 17-15-00 = 17.25 x 60 = 1035 - 37.713333 = 997.28667 / 60 = 16.621444 = 16-37-17 LMT GMT today referred as UTC is the Coordinated Universal Time based on the Greenwich Meridian and is valid all over the world. GMT is very important for the celestial navigation and to determine sunrise and sunset. LMT is the Local Mean Time based on the current longitude. I don't know if it is implemented in Silent Hunter 4, that would have to be tested. I hope, I could help a little bit

02-11-18, 12:18 PM	#20
Gaius Godefridus Nub Join Date: Jul 2016 Posts: 2 Downloads: 155 Uploads: 0	Thanks Aktungbby

04-02-18, 06:27 PM	#24
aanker Pacific Thunder Join Date: Apr 2004 Location: Yellow Sea Posts: 1,896 Downloads: 236 Uploads: 14	Thank you Nathaniel B. I'd seen others but never this one. Happy Hunting!

04-02-18, 08:29 PM	#25
Sean C Grey Wolf Join Date: Jun 2017 Location: Norfolk, VA Posts: 904 Downloads: 12 Uploads: 2	You're welcome! That is a chart I made for my own reference and I hadn't posted it anywhere until now.

04-07-18, 10:02 AM	#26
LCQ_SH Lieutenant Join Date: May 2012 Posts: 266 Downloads: 175 Uploads: 0	good question. o.o