programming error

[riadd123]

Arduino: 1.8.19 (Windows 10), Board: "Arduino Pro or Pro Mini, ATmega328P (5V, 16 MHz)"

In file included from C:\Users\SEFATF~1\AppData\Local\Temp\arduino_modified_sketch_212439\RetroWatchArduino_u8glib_no_button.ino:32:0:

bitmap.h:1269:42: error: variable 'bitmap_array' must be const in order to be put into read-only section by means of 'attribute((progmem))'

PROGMEM const unsigned char*bitmap_array[] = {

                                      ^

RetroWatchArduino_u8glib_no_button:123:32: error: variable 'weekString' must be const in order to be put into read-only section by means of 'attribute((progmem))'

PROGMEM const char* weekString[] = {"", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};

                            ^

RetroWatchArduino_u8glib_no_button:124:32: error: variable 'ampmString' must be const in order to be put into read-only section by means of 'attribute((progmem))'

PROGMEM const char* ampmString[] = {"AM", "PM"};

                            ^

RetroWatchArduino_u8glib_no_button:161:30: error: variable 'strIntro' must be const in order to be put into read-only section by means of 'attribute((progmem))'

PROGMEM const char* strIntro[] = {"Retro", "Watch", "Arduino v1.0"};

                          ^

exit status 1

variable 'bitmap_array' must be const in order to be put into read-only section by means of 'attribute((progmem))'

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what should i do?

[VrajChariot]

PROGMEM const char* const weekString[] = {"", "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"};
PROGMEM const char* const ampmString[] = {"AM", "PM"};

use this