forked from STI/Astroport.ONE
45 lines
1.5 KiB
Bash
Executable File
45 lines
1.5 KiB
Bash
Executable File
#!/bin/bash
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# Correct Time to give the real 20H12 time (on UTC table) at a given longitude
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# Input longitude in degrees (positive for East, negative for West)
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longitude=$1
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# Check if longitude is numeric
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if ! [[ $longitude =~ ^[+-]?[0-9]+(\.[0-9]+)?$ ]]; then
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echo "Invalid longitude input. Please provide a valid numeric value."
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exit 1
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fi
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# Determine if it's East or West longitude
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if [ $(echo "$longitude >= 0" | bc) -eq 1 ]; then
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direction="East"
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else
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direction="West"
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fi
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# Calculate the time offset in minutes using awk for floating-point arithmetic
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offset_minutes=$(echo "$longitude * 4" | bc)
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# Determine if it's ahead or behind UTC
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if [ "$direction" == "West" ]; then
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offset_minutes=$(echo "$offset_minutes * -1" | bc)
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fi
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# Calculate the solar noon time in UTC (12:00 PM)
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solar_noon_utc_seconds=$((12 * 3600))
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# Adjust the solar noon time by the offset in seconds
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local_solar_noon_seconds=$(echo "$solar_noon_utc_seconds + ( $offset_minutes * 60 )" | bc | cut -d '.' -f 1)
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# Convert the local solar noon time to hours, minutes, and seconds
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local_solar_noon_time=$(date -u -d "@$local_solar_noon_seconds" +%H:%M:%S)
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# Add 8 hours and 12 minutes to the local solar noon time
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new_time_seconds=$((local_solar_noon_seconds + 8*3600 + 12*60))
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new_time=$(date -u -d "@$new_time_seconds" +%H:%M:%S)
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echo "Longitude: $longitude degrees $direction"
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echo "Time Offset: $offset_minutes minutes"
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echo "Local Solar Noon (midday) Time: $local_solar_noon_time"
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echo "Local Solar Noon + 8h 12mn:
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$new_time"
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